Patient interface and method for making same

ABSTRACT

A nasal patient interface for delivery of a supply of pressurised air or breathable gas to an entrance of a patient&#39;s airways comprising: a cushion member that includes a retaining structure and a seal-forming structure permanently connected to the retaining structure; a frame member attachable to the retaining structure; and a positioning and stabilising structure releasably attachable to the frame member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of US Provisional Appln. No.61/811,385 filed on 12 Apr. 2013; 61/817,674 filed on 30 Apr. 2013;61/823,192 filed on 14 May 2013; 61/888,357 filed on 8 Oct. 2013; and61/915,320 filed Dec. 12, 2013; EP Non-Provisional Appln. No. 13163546.8filed on 12 Apr. 2013; AU Provisional Appln. Nos. 2013900168 filed on 18Jan. 2013; 2013902305 filed on 24 Jun. 2013; 2013902945 filed on 6 Aug.2013; and 2013903509 filed on 12 Sep. 2013. Each of the applicationsreferenced above is incorporated herein by reference in its entirety.

BACKGROUND OF THE TECHNOLOGY

(1) Field of the Technology

The present technology relates to one or more of the diagnosis,treatment and amelioration of respiratory disorders, and to proceduresto prevent respiratory disorders. In particular, the present technologyrelates to medical devices, and their use for treating respiratorydisorders and for preventing respiratory disorders.

(2) Description of the Related Art

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower,shorter and more numerous as they penetrate deeper into the lung. Theprime function of the lungs is gas exchange, allowing oxygen to movefrom the air into the venous blood and carbon dioxide to move out. Thetrachea divides into right and left main bronchi, which further divideeventually into terminal bronchioles. The bronchi make up the conductingairways, and do not take part in gas exchange. Further divisions of theairways lead to the respiratory bronchioles, and eventually to thealveoli. The alveolated region of the lung is where the gas exchangetakes place, and is referred to as the respiratory zone.

A range of respiratory disorders exist.

Obstructive Sleep Apnoea (OSA), a form of Sleep Disordered Breathing(SDB), is characterized by occlusion of the upper air passage duringsleep. It results from a combination of an abnormally small upper airwayand the normal loss of muscle tone in the region of the tongue, softpalate and posterior oropharyngeal wall during sleep. The conditioncauses the affected patient to stop breathing for periods typically of30 to 120 seconds duration, sometimes 200 to 300 times per night. Itoften causes excessive daytime somnolence, and it may causecardiovascular disease and brain damage. The syndrome is a commondisorder, particularly in middle aged overweight males, although aperson affected may have no awareness of the problem. See U.S. Pat. No.4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is a disorder of a patient's respiratorycontroller in which there are rhythmic alternating periods of waxing andwaning ventilation, causing repetitive de-oxygenation and re-oxygenationof the arterial blood. It is possible that CSR is harmful because of therepetitive hypoxia. In some patients CSR is associated with repetitivearousal from sleep, which causes severe sleep disruption, increasedsympathetic activity, and increased afterload. See U.S. Pat. No.6,532,959 (Berthon-Jones).

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnoea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

Otherwise healthy individuals may take advantage of systems and devicesto prevent respiratory disorders from arising.

Systems

One known product used for treating SDB is the S9 Sleep Therapy System,manufactured by ResMed.

Therapy

Nasal Continuous Positive Airway Pressure (CPAP) therapy has been usedto treat Obstructive Sleep Apnea (OSA). The hypothesis is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion by pushing the soft palate and tongueforward and away from the posterior oropharyngeal wall.

Non-invasive ventilation (NIV) has been used to treat OHS, COPD, MD andChest Wall disorders.

Patient Interface

The application of a supply of air at positive pressure to the entranceof the airways of a patient is facilitated by the use of a patientinterface, such as a nasal mask, full-face mask or nasal pillows. Afull-face mask includes a mask with one sealing-forming portion coveringat least the nares and mouth, or more than one sealing-forming portionto individually cover at least the nares and mouth. A range of patientinterface devices are known, however a number of them suffer from beingone or more of obtrusive, aesthetically undesirable, poorly fitting,difficult to use and uncomfortable especially when worn for long periodsof time or when a patient is unfamiliar with a system. Masks designedsolely for aviators, as part of personal protection equipment or for theadministration of anaesthetics may be tolerable for their originalapplication, but nevertheless be undesirably uncomfortable to be wornfor extended periods, for example, while sleeping.

Seal-Forming Structure

Patient interfaces typically include a seal-forming structure.

One type of seal-forming structure extends around the periphery of thepatient interface, and is intended to seal against the user's face whenforce is applied to the patient interface with the seal-formingstructure in confronting engagement with the user's face. Theseal-forming structure may include an air or fluid filled cushion, or amolded or formed surface of a resilient seal element made of anelastomer such as a rubber. With this type of seal-forming structure, ifthe fit is not adequate, there will be gaps between the seal-formingstructure and the face, and additional force will be required to forcethe patient interface against the face in order to achieve a seal.

Another type of seal-forming structure incorporates a flap seal of thinmaterial so positioned about the periphery of the mask so as to providea self-sealing action against the face of the user when positivepressure is applied within the mask Like the previous style ofseal-forming structure, if the match between the face and the mask isnot good, additional force may be required to effect a seal, or the maskmay leak. Furthermore, if the shape of the seal-forming structure doesnot match that of the patient, it may crease or buckle in use, givingrise to leaks.

Another form of seal-forming structure may use adhesive to effect aseal. Some patients may find it inconvenient to constantly apply andremove an adhesive to their face.

A range of patient interface seal-forming structure technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.

Positioning and Stabilising

A seal-forming structure of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus a variety of techniques have been usedto position the seal-forming structure, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US Patentpublication US 2010/0000534.

Another technique is the use of one or more straps and stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

Rigid elements, also known as “rigidisers”, have been used withstretchable headgears previously. One known problem is associated withthe fact that a rigidiser permanently attached (e.g. laminated orstitched) to a large area of the stretchable material limits thestretchable length of the material, thus affecting the elasticproperties of the entire headgear. Another issue concerns cleaning theheadgear which would require both the rigidiser and stretchable materialto be washed together as they are permanently attached to each other.

Vent Technologies

Some forms of patient interface systems may include a vent to allow thewashout of exhaled carbon dioxide. Many such vents are noisy. Others mayblock in use and provide insufficient washout. Some vents may bedisruptive of the sleep of a bed-partner of the patient, e.g. throughnoise or focussed airflow. Some vents cannot be properly cleaned andmust be discarded after they become blocked. Some vents are intended tobe used for a short duration of time, i.e. less than three months, andtherefore are manufactured from fragile material to prevent washing orfrequent washing so as to encourage more frequent replacement of thevent.

ResMed Limited has developed a number of improved mask venttechnologies. See WO 1998/034,665; WO 2000/078,381; U.S. Pat. No.6,581,594; US patent application; US 2009/0050156; US Patent Application2009/0044808.

Table of noise of prior masks (ISO 17510-2:2007, 10 cm H₂O pressure at 1m)

A- A- weighted weighted sound sound power pressure level dbA dbA Mask(uncer- (uncer- Year Mask name type tainty) tainty) (approx.) Glue-on(*) nasal 50.9 42.9 1981 ResCare standard (*) nasal 31.5 23.5 1993ResMed Mirage (*) nasal 29.5 21.5 1998 ResMed UltraMirage nasal 36 (3)28 (3) 2000 ResMed Mirage Activa nasal 32 (3) 24 (3) 2002 ResMed MirageMicro nasal 30 (3) 22 (3) 2008 ResMed Mirage nasal 29 (3) 22 (3) 2008SoftGel ResMed Mirage FX nasal 26 (3) 18 (3) 2010 ResMed Mirage nasal 3729 2004 Swift (*) pillows ResMed Mirage nasal 28 (3) 20 (3) 2005 SwiftII pillows ResMed Mirage nasal 25 (3) 17 (3) 2008 Swift LT pillowsResMed Swift FX nasal 25 (3) 17 (3) 2011 pillows ResMed Mirage seriesfull face 31.7 23.7 2000 I, II (*) ResMed UltraMirage full face 35 (3)27 (3) 2004 ResMed Mirage full face 26 (3) 18 (3) 2006 Quattro ResMedMirage full face 27 (3) 19 (3) 2008 Quattro FX (* one specimen only,measured using test method specified in ISO3744 in CPAP mode at 10cmH₂O)

Sound pressure values of a variety of objects are listed below

A-weighted sound pressure dbA Object (uncertainty) Notes Vacuum cleaner:Nilfisk 68 ISO3744 at Walter Broadly Litter Hog: 1 m distance B+ GradeConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 20

Nasal Pillow Technologies

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT™ nasal pillows mask, SWIFT II™ nasal pillows mask,SWIFT LT™ nasal pillows mask, SWIFT FX™ nasal pillows mask and LIBERTYfull-face mask. The following patent applications, assigned to ResMedLimited, describe nasal pillows masks: International Patent ApplicationWO2004/073,778 (describing amongst other things aspects of ResMed SWIFT™nasal pillows), US Patent Application 2009/0044808 (describing amongstother things aspects of ResMed SWIFT LT nasal pillows); InternationalPatent Applications WO 2005/063,328 and WO 2006/130,903 (describingamongst other things aspects of ResMed LIBERTY™ full-face mask);International Patent Application WO 2009/052,560 (describing amongstother things aspects of ResMed SWIFT FX™ nasal pillows).

PAP Device

The air at positive pressure is typically supplied to the airway of apatient by a PAP device such as a motor-driven blower. The outlet of theblower is connected via a flexible delivery conduit to a patientinterface as described above.

Mandibular Repositioning

A mandibular repositioning device (MRD) is one of the treatment optionsfor sleep apnea. It is a custom made, adjustable oral applianceavailable from a dentist that holds the lower jaw in a forward positionduring sleep. This mechanical protrusion expands the space behind thetongue, puts tension on the pharyngeal walls to reduce collapse of theairway and diminishes palate vibration.

BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the diagnosis, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost,efficacy, ease of use and manufacturability.

One aspect of the present technology relates to apparatus used in thediagnosis, amelioration, treatment or prevention of a respiratorydisorder.

Another aspect of the present technology relates to apparatus fortreating a respiratory disorder including a patient interface, an aircircuit, and a source of air at positive pressure.

Another aspect of the present technology relates to methods used in thediagnosis, amelioration, treatment or prevention of a respiratorydisorder.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of breathable gas at a continuouslypositive pressure with respect to ambient air pressure to an entrance tothe patient's airways including at least entrance of a patient's nares,wherein the patient interface is configured to maintain a therapypressure in a range of about 4 cm H₂O to about 30 cm H₂O above ambientair pressure in use, throughout the patient's respiratory cycle, whilethe patient is sleeping, to ameliorate sleep disordered breathing. In anexample, the patient interface includes a cushion assembly including aseal-forming structure adapted to form a seal against the patient'sairways and a plenum chamber pressurised at a pressure above ambientpressure in use, a positioning and stabilising structure to maintain thecushion assembly in sealing contact with an area surrounding an entranceto the patient's airways while maintaining a therapeutic pressure at theentrance to the patient's airways, a gas washout vent configured toallow a flow of patient exhaled CO₂ to an exterior of the patientinterface to minimise rebreathing of exhaled CO₂ by the patient, and aframe assembly to releasably engage the cushion assembly and provide aconnection to the positioning and stabilising structure.

One aspect of one form of the present technology is a patient interfacewith a seal-forming structure that is removable for cleaning. It is thedesire of the present technology to provide a patient interface that islight-weight compared to prior art patient interfaces, more unobtrusivecompared to prior art patient interfaces and more quiet in use comparedto prior art patient interfaces. It is also desirable to provide apatient interface that is intuitive to a patient when connecting maskcomponents prior to commencement of therapy and is also simple to adjustand wear for therapy.

An aspect of one form of the present technology is a patient interfacehaving a seal-forming structure that is locatable in position on thepatient interface via a hard-to-hard connection. Another aspect of oneform of the present technology is seal-forming structure of a patientinterface that is removable for cleaning without requiring disconnectionof a headgear portion of the patient interface. Another aspect of thepresent invention is a patient interface having a seal-forming structurethat is removable from a frame assembly by squeezing lateral sides ofthe seal-forming structure to allow disengagement of a retainingstructure provided to the seal-forming structure from the frameassembly.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's airways including a cushion member thatincludes a retaining structure and a seal-forming structure permanentlyconnected to the retaining structure, and a frame member, wherein theretaining structure and the frame member are repeatedly engageable withand disengageable from one another, wherein a gas chamber is formed atleast in part by engagement of the cushion member and the frame member,wherein an increase in air pressure within the cushion member causes asealing force between the seal-forming structure and the frame member toincrease, and wherein the seal-forming structure serves both nares ofthe patient with a single orifice. The seal-forming structure may beco-molded with the retaining structure. The cushion member may berepeatedly removably engageable with and disengageable from the framemember by pinching two opposing locations on lateral sides of thecushion member. The cushion member may comprise a sealing lip that sealsagainst the frame member when the retaining structure and frame memberare attached to one another, and when air pressure increases within thecushion member, the sealing force may be increased. The sealing lip maybe a continuous inner peripheral edge integral to the seal-formingstructure. The retaining structure and the frame member may be morerigid than the seal-forming structure. The cushion member may comprise aplenum chamber having a posterior wall that is constructed and arrangedto be located adjacent an upper lip of the patient in use, and theplenum chamber may be located between the retaining structure and theseal-forming structure. The patient interface may further comprise apositioning and stabilising structure or a connector for a positioningand stabilising structure directly connected to the frame member. Theplenum chamber may comprise the sealing lip, the sealing lip beinglocated at a plenum connection region of the plenum chamber, and thesealing lip may be adapted to form a pneumatic seal between the cushionmember and the frame member. The sealing lip may be disposed about apartial or entire interior periphery or a partial or entire exteriorperiphery of the plenum chamber. The patient interface may furthercomprise an additional sealing lip disposed about a partial or entireinterior periphery or a partial or entire exterior periphery of theplenum chamber. The sealing lip may depend from the plenum chamber at anangle and in a direction substantially opposite of the seal-formingstructure. The sealing lip may be constructed and arranged such that itis deformable in a direction substantially toward the seal-formingstructure such that a pneumatic seal may be formed between the plenumchamber and the frame when the frame is attached to the plenum chambervia the plenum connection region. The sealing lip and the plenum chambermay comprise one piece. The plenum connection region and the plenumchamber may be fixedly attached by co-molding or injection molding. Theplenum connection region and the plenum chamber may comprise differentmaterials, and the plenum chamber may comprise a softer material thanthe plenum connection region. The plenum chamber may comprise anelastomeric material and the plenum connection region may comprisethermoplastic polymer, high durometer silicone, thermoset orthermoplastic elastomer having a higher durometer than the elastomericmaterial of the plenum chamber. The plenum connection region and framemay be made from an equivalent material. The plenum connection regionmay comprise at least one retention feature to facilitate connectionwith the frame, and the frame may comprise at least one complementaryframe connection region to receive the at least one retention featurecorresponding thereto. In an example, complete engagement of the atleast one retention feature to the at least one frame connection regionmay generate an audible click when the plenum connection region isattached to the frame. The at least one retention feature may comprise afirst retention feature and a second retention feature and the at leastone frame connection region may comprise a first frame connection regionand a second frame connection region. The first retention feature may becomplementarily dimensioned with respect to the first frame connectionregion such that the second retention feature cannot be engaged to thefirst frame connection region. The retention feature may be a barb andthe frame connection region a slot.

Another aspect of one form of the present technology is a patientinterface to provide breathable gas to a patient. The patient interfaceincludes a plenum chamber having a plenum connection region, aseal-forming structure disposed on the plenum chamber, the seal-formingstructure serving both nares of the patient with a single orifice, and aframe comprising a frame connection region and a headgear connectionregion, wherein the frame connection region is configured for attachmentto the plenum chamber at the plenum connection region, and wherein asealing lip is adapted to form a pneumatic seal between the plenumconnection region and the frame connection region. The frame connectionregion may comprise at least one retention feature to facilitateconnection with the plenum connection region, and the plenum connectionregion may comprise at least one complementary connection region toreceive the at least one retention feature corresponding thereto. The atleast one retention feature may be a barb, the barb having a leadingsurface and a trailing surface and the at least one complementaryconnection region may comprise a lead-in surface and a retainingsurface.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's nasal airways only. The patient interfaceincludes a cushion member that includes a retaining structure and aseal-forming structure permanently connected to the retaining structure,the seal-forming structure serving both nares of the patient with asingle orifice, and a frame member, wherein the retaining structure andthe frame member are repeatedly engageable with and disengageable fromone another, and wherein an increase in air pressure within the cushionmember causes a sealing force between the seal-forming structure and theframe member to increase.

Another aspect of one form of the present technology is a cushion memberfor a patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways. The cushion memberincludes a retaining structure for repeatable engagement with anddisengagement from a frame member, and a seal-forming structurepermanently connected to the retaining structure, the seal-formingstructure serving both nares of the patient with a single orifice,wherein the seal-forming structure is made from a first material and theretaining structure is made from a second material with differentmechanical characteristics from the first material and the secondmaterial is more rigid than the first material, and wherein an increasein air pressure within the cushion member causes a sealing force betweenthe seal-forming structure and the frame member to increase. The firstmaterial may be silicone and the second material may be silicone with ahigher durometer than the first material. The cushion member may furthercomprise a plenum chamber located between the retaining structure andthe seal-forming structure. The first material may permit theseal-forming structure to readily conform to finger pressure and thesecond material may prevent the retaining structure from readilyconforming to finger pressure.

Another aspect of one form of the present technology is a cushion memberfor a patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways. The cushion memberincludes a retaining structure for repeatable engagement with anddisengagement from a frame member, and a seal-forming structurepermanently connected to the retaining structure, the seal-formingstructure serving both nares of the patient with a single orifice,wherein the seal-forming structure is made from a first material and theretaining structure is made from a second material that is differentfrom the first material and is more rigid than the first material, andwherein the first material permits the seal-forming structure to readilyconform to finger pressure and the second material prevents theretaining structure from readily conforming to finger pressure.

Another aspect of one form of the present technology is a cushion memberfor a patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways. The cushion memberincludes a retaining structure for repeatable engagement with anddisengagement from a frame member, and a seal-forming structureconnected to the retaining structure, the seal-forming structure servingboth nares of the patient with a single orifice, wherein theseal-forming structure is made from a first material and the retainingstructure is made from a second material that is different from thefirst material and is more rigid than the first material, and whereinthe retaining structure has a continuous peripheral edge on an anteriorside that contacts the frame member.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's airways, including a cushion member thatincludes a seal-forming structure that serves both nares of the patientwith a single orifice, a frame member, and a gas delivery tube to supplybreathable gas from a respiratory apparatus that is permanentlyconnected to the frame member. The gas delivery tube includes a helicalcoil comprised of a plurality of adjacent coils, each coil separated bya width and having an outer surface defining a coil diameter, and a webof material coaxial to the helical coil attached to the helical coilbetween adjacent ones of the plurality of adjacent coils and having atleast one fold extending radially outward between adjacent ones of theplurality of adjacent coils, the at least one fold defined by apredetermined fold line. A vertex of the at least one fold defines afold diameter. When the gas delivery tube is in a neutral state, thecoil diameter is substantially equal to the fold diameter and theadjacent coils are separated from each other in the neutral state, andthe helical coil and the web of material are made from a thermoplasticmaterial. The gas delivery tube includes one of three different states:a neutral state wherein the gas delivery tube comprises a neutrallength, an extended state wherein the gas delivery tube is extendedalong its longitudinal axis to an extended length that is greater thanthe neutral length, and a compressed state wherein the gas delivery tubeis compressed along its longitudinal axis to a compressed length that isless than the neutral length.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's airways, including a cushion member thatincludes a seal-forming structure that serves both nares of the patientwith a single orifice, a frame member, and a gas delivery tube to supplybreathable gas from a respiratory apparatus that is permanentlyconnected to the frame member. The gas delivery tube includes a helicalcoil comprised of a plurality of adjacent coils, each coil separated bya width, a web of material coaxial to the helical coil attached to thehelical coil between adjacent ones of the plurality of adjacent coilsand having at least one fold extending radially outward between adjacentones of the plurality of adjacent coils, the at least one fold definedby a predetermined fold line, a first end cuff for permanently andnon-rotatably connecting the tube to the frame member, and a second endcuff for releasably and rotatably connecting with a tube adapter. Thegas delivery tube includes one of three different states: a neutralstate wherein the gas delivery tube comprises a neutral length, anextended state wherein the gas delivery tube is extended along itslongitudinal axis to an extended length that is greater than the neutrallength, and a compressed state wherein the gas delivery tube iscompressed along its longitudinal axis to a compressed length that isless than the neutral length.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's airways, including a cushion member thatincludes a seal-forming structure that serves both nares of the patientwith a single orifice, a frame member, and a gas delivery tube to supplybreathable gas from a respiratory apparatus that is permanentlyconnected to the frame member. The gas delivery tube includes aplurality of coils each separated by a width, and a web of materialcoaxial to the coils attached to the coils between adjacent ones of theplurality of coils and having at least one fold extending radiallyoutward between adjacent ones of the plurality of coils, the at leastone fold defined by a peak. The web of material includes a humpedportion adjacent to a first side of the coils and a slanted portionadjacent to a second side of the coils, the second side opposite saidfirst side. When the gas delivery tube is in a neutral state a slope ofthe web of material is steeper from the slanted portion to the adjacentpeak than a slope of the web of material from the humped portion to theadjacent peak.

Another aspect of one form of the present technology is a patientinterface for delivery of a supply of pressurised air or breathable gasto an entrance of a patient's airways, including a cushion member thatincludes a seal-forming structure that serves both nares of the patientwith a single orifice, a frame member, and a gas delivery tube to supplybreathable gas from a respiratory apparatus that is permanentlyconnected to the frame member. The gas delivery tube includes a helicalcoil comprised of a plurality of adjacent coils, each coil separated bya width, and a web of material coaxial to the helical coil attached tothe helical coil between adjacent ones of the plurality of adjacentcoils. The width separating adjacent ones of the plurality of adjacentcoils is substantially equal to a width of the helical coil when the gasdelivery tube is in a neutral state.

Another aspect of one form of the present technology is a cushion memberfor a patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways, the cushion memberincluding a retaining structure for repeatable engagement with anddisengagement from a frame member, and a seal-forming structureconnected to the retaining structure, the seal-forming structure servingboth nares of the patient with a single orifice. The seal-formingstructure is made from a first material and the retaining structure ismade from a second material that is different from the first materialand is more rigid than the first material. The seal-forming structurehas a substantially flat lower wall to alleviate pressure on thepatient's upper lip.

An aspect of one form of the present technology is a method ofmanufacturing the patient interface described herein. It is a desire ofthe present technology to provide a method of manufacture that has lesscomplexity than methods of manufacturing prior art patient interfaces toincrease manufacturing efficiency, uses less raw materials and requiresless assembly time by operators.

Another aspect of one form of the present technology is a patientinterface that is molded or otherwise constructed with a clearly definedperimeter shape which is intended to match that of an intended wearer(i.e. patient) and be intimate and conform with the face of the intendedwearer.

Another aspect of one form of the present technology is a headgear clipfor a positioning and stabilising structure of a patient interfaceincluding a mechanical structure to mechanically engage the headgearclip to a headgear connection point of a frame assembly and allow theheadgear clip to rotate relative to the headgear connection point, amagnet to magnetically engage the headgear clip with the headgearconnection point, and a slot to receive a headgear strap passingtherethrough, wherein the mechanical structure prevents lineardisplacement of the headgear clip in a direction substantially parallelto the Frankfort horizontal direction when headgear tension is appliedand the mechanical structure includes a raised wall that defines a spaceadapted to receive the headgear connection point. The raised wall may bein the shape of a semi-circle, and the headgear connection point mayinclude a cylindrical portion providing a raised surface structured toengage the raised wall. The magnet may be held within the headgear clipby a top layer of plastic material and a bottom layer of plasticmaterial. The mechanical structure may be a raised wall projecting awayfrom the bottom layer of plastic material. The raised wall may projectfrom a circumferential portion around the magnet. The raised wall mayhave a semi-circular cross-section. The magnet may be fully encased inplastic material. The slot may be elongate having its longitudinal axisoriented parallel with a nominal vertical axis in use. When the headgearclip is engaged with the headgear connection point and headgear tensionis applied, the slot may be unobstructed by the lower arm and frameassembly. The headgear connection point may comprise a magnet. Themagnet of the headgear connection point may be fully encased in plasticmaterial. The magnet of the headgear connection point may be fullyencased within the lower arm. The headgear connection point may be araised surface from a lower arm of the frame assembly such it abuts theraised wall when headgear tension is applied. When headgear tension isapplied by adjusting the length of the headgear strap, the headgear clipmay maintain mechanical and magnetic engagement with the lower arm androtate relative to the lower arm. The magnet of the headgear clip and/orthe headgear connection point may be a ferromagnetic material, permanentmagnet or electromagnet.

Another aspect of one form of the present technology is a frame for apatient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways. The frame includesa main body and at least one arm extending from the main body. The atleast one arm provides a headgear connection point at a distal end ofthe arm. The headgear connection point includes a magnet structured tomagnetically interface with a positioning and stabilising structure ofthe patient interface.

Another aspect of one form of the present technology is a frame for apatient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways. The frame includesa connection port adapted to communicate with a tube for the delivery ofthe supply of pressurised air or breathable gas, a vent structured toallow washout of exhaled air or gas from the patient interface, and abaffle structured to segregate the exhaled air or gas via the vent fromthe supply of pressurised air or breathable gas via the connection port.

Another aspect of one form of the present technology is a frame assemblyfor a patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's nasal airways only. Theframe assembly includes a ring member, lower arms extending from lowerarm connection points radially positioned on the ring member, a joiningmember extending posteriorly from the ring member at an upper positionon the ring member, and upper arms extending from an upper armconnection point at a distal end of the joining member such that thelower arm connection points are in a position anterior from the upperarm connection point. The upper arm connection point and lower armconnection points are spaced apart at a predetermined distance toprovide a maximum tilting range for the frame assembly relative to thepatient's face.

Another aspect of one form of the present technology is a method fordisassembling a patient interface for delivery of a supply ofpressurised air or breathable gas to an entrance of a patient's airways.The method includes squeezing or pinching lateral sides of aseal-forming structure to allow disengagement of the seal-formingstructure from a frame.

An aspect of one form of the present technology is a method ofmanufacturing the patient interface.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

Treatment Systems

FIG. 1 a shows a system in accordance with the present technology. Apatient 1000 wearing a patient interface 3000, receives a supply of airat positive pressure from a PAP device 4000. Air from the PAP device4000 is humidified in a humidifier 5000, and passes along an air circuit4170 to the patient 1000.

FIG. 1 b shows a PAP device 4000 in use on a patient 1000 with a nasalmask.

FIG. 1 c shows a PAP device 4000 in use on a patient 1000 with afull-face mask.

Therapy Respiratory System

FIG. 2 a shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2 b shows a view of a human upper airway including the nasalcavity, nasal bone, lateral nasal cartilage, greater alar cartilage,nostril, lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

Facial Anatomy

FIG. 2 c is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermillion, lowervermillion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion.

FIG. 2 d is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, otobasion superiorand otobasion inferior. Also indicated are the directions superior &inferior, and anterior & posterior.

FIG. 2 e is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated.

FIG. 2 f shows a base view of a nose.

FIG. 2 g shows a side view of the superficial features of a nose.

FIG. 2 h shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage and fibrofatty tissue.

FIG. 2 i shows a medial dissection of a nose, approximately severalmillimeters from a sagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage.

FIG. 2 j shows a front view of the bones of a skull including thefrontal, temporal, nasal and zygomatic bones. Nasal concha areindicated, as are the maxilla, mandible and mental protuberance.

FIG. 2 k shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter sternocleidomastoidand trapezius.

FIG. 2 l shows an anterolateral view of a nose.

Pap Device and Humidifier

FIG. 3 a shows an exploded view of a PAP device according to an exampleof the present technology.

FIG. 3 b shows a perspective view of a humidifier in accordance with oneform of the present technology.

FIG. 3 c shows a schematic diagram of the pneumatic circuit of a PAPdevice in accordance with one form of the present technology. Thedirections of upstream and downstream are indicated.

Patient Interface

FIG. 4 shows a short tube in a neutral state according to an example ofthe present technology.

FIG. 5 shows a side view of a short tube in a compressed state accordingto an example of the present technology.

FIG. 6 shows a side view of a short tube in an elongated state accordingto an example of the present technology.

FIG. 7 shows a side view of a short tube in a curved state according toan example of the present technology.

FIG. 8 shows a cross-sectional view of a short tube taken along line163-163 as shown in FIG. 7 according to an example of the presenttechnology.

FIG. 9 shows a perspective view of a short tube in a curved andelongated state according to an example of the present technology.

FIGS. 10 to 14 show a tube in accordance with one form of the presenttechnology being elongated by a distance of 30 mm, 60 mm, 90 mm, and 120mm with a lower end of the tube held in a fixed position with itslongitudinal axis at its lower end being perpendicular to the directionof elongation before elongation commences.

FIGS. 15 to 19 show a ResMed™ Swift FX™ Nasal Pillows Mask tube beingelongated by a distance of 30 mm, 60 mm, 90 mm, and 120 mm with a lowerend of the tube held in a fixed position with its longitudinal axis atits lower end being perpendicular to the direction of elongation beforeelongation commences.

FIGS. 20 to 24 show a Philips™ Respironics™ GoLife™ Nasal Pillows Masktube being elongated by a distance of 30 mm, 60 mm, 90 mm, and 120 mmwith a lower end of the tube is held a fixed position with itslongitudinal axis at its lower end being perpendicular to the directionof elongation before elongation commences.

FIGS. 25 to 29 show a Philips™ Respironics™ Wisp™ Nasal Mask tube beingelongated by a distance of 30 mm, 60 mm, 90 mm, and 120 mm with a lowerend of the tube held in a fixed position with its longitudinal axis atits lower end being perpendicular to the direction of elongation beforeelongation commences.

FIG. 30 is a perspective view of a patient interface shown on apatient's head to indicate the approximate relative location of theheadgear in use according to a first example of the present technology.

FIGS. 31 to 34 are sequential views showing exemplary steps for donninga patient interface according to the first example of the presenttechnology.

FIG. 35 is a perspective view of a patient interface partially showing ashort tube according to the first example of the present technology.

FIG. 36 is a perspective view of a patient interface showing an entireshort tube according to the first example of the present technology.

FIG. 37 is a perspective view of a patient interface shown on apatient's head to indicate the approximate relative location of theheadgear in use according to a second example of the present technology.

FIGS. 38 to 41 are sequential views showing exemplary steps for donninga patient interface according to the second example of the presenttechnology.

FIGS. 42 to 49 show various views of a frame according to a thirdexample of the present technology.

FIGS. 50 to 52 show various views of a pull-through prevention featureaccording to an example of the present technology.

FIG. 53 is a perspective side view of a frame for a patient interfaceaccording to a fourth example of the present technology.

FIG. 54 is a perspective side view of a frame partially showing a shorttube connected to the frame for a patient interface according to thefourth example of the present technology.

FIG. 55 is a front view of the frame of FIG. 53.

FIG. 56 is a side view of the frame of FIG. 54.

FIG. 57 is a bottom view of the frame of FIG. 54.

FIG. 58 is a top view of the frame of FIG. 54.

FIG. 59 is a perspective side view of a frame for a patient interfaceaccording to a fifth example of the present technology, not showing avent.

FIG. 60 is a front view of the frame of FIG. 59.

FIG. 61 is a side view of the frame of FIG. 59.

FIG. 62 is a bottom view of the frame of FIG. 59.

FIG. 63 is a top view of the frame of FIG. 59.

FIG. 64 is a side perspective view of a patient interface shown on apatient's head to indicate the approximate relative location of theheadgear in use according to the fourth example of the presenttechnology.

FIG. 65 is a front view of a patient interface shown on a patient's headto indicate the approximate relative location of the headgear in useaccording to the fourth example of the present technology.

FIG. 66 is a side view of a patient interface shown on a patient's headto indicate the approximate relative location of the headgear in useaccording to the fourth example of the present technology.

FIG. 67 is a rear view of a patient interface shown on a patient's headto indicate the approximate relative location of the headgear in useaccording to the fourth example of the present technology.

FIG. 68 is a close up perspective view of a patient interface shown on apatient's head to indicate the approximate relative location of a nasalcushion in use according to the fourth example of the presenttechnology.

FIG. 69 is a perspective view of a patient interface showing a cushionclip separated from a frame according to the fourth example of thepresent technology.

FIG. 70 is a perspective view partially showing a headgear clippositioned on a lower headgear strap of a positioning and stabilisingstructure for a patient interface according to the fourth example of thepresent technology.

FIG. 71 is a top planar view of a seal-forming structure for a patientinterface according to the fourth example of the present technology.

FIG. 72 is a perspective view of a patient interface according to thefourth example of the present technology.

FIG. 73 is a rear view of a seal-forming structure of a patientinterface according to the fourth example of the present technology.

FIG. 74 is an enlarged view of the seal-forming structure of FIG. 73

FIG. 75 is a rear view of a cushion assembly according to the fourthexample of the present technology.

FIG. 76 is a rear view of a cushion assembly according to the fourthexample of the present technology.

FIG. 77 shows a magnified view of the frame of FIG. 53, showing a magnetpositioned on a lower arm.

FIG. 78 shows a patient interface according to the present technology,comprising a frame molded to the cuff of the short tube shown in FIGS.54 to 58, the patient interface further comprising a cushion assemblysealingly engaged to the frame in a releasable manner.

FIG. 79 shows a patient interface according to another example of thepresent technology. The patient interface comprises a positioning andstabilising structure comprising magnets. The positioning andstabilising structure is releasably engaged to a frame with a vent andis molded to the cuff of a short tube. The frame is releasably engagedto a cushion assembly.

FIG. 80 is a sectional perspective view of a cushion assembly accordingto the fourth example of the present technology.

FIG. 81 is a sectional side view of a cushion assembly according to thefourth example of the present technology.

FIG. 82 is an exploded perspective view of a patient interface accordingto an example of the present technology showing assemblies that aredetachable.

FIG. 83 is an exploded perspective view of a frame assembly without ashort tube and a cushion assembly according to the fourth example of thepresent technology.

FIG. 84 is a perspective view of a patient interface according to thefourth example of the present technology.

FIG. 85 is a rear perspective view of a patient interface according tothe fourth example of the present technology without headgear strapsshown.

FIG. 86 is a side perspective view of a patient interface according tothe fourth example of the present technology showing assemblies attachedto each other.

FIG. 87 is a front perspective view of a patient interface according tothe fourth example of the present technology showing assemblies attachedto each other.

FIG. 88 is a perspective view of a patient interface according to thefourth example of the present technology without headgear straps shown.

FIG. 89 is an enlarged anterior cross-sectional view of a plenum chamberin accordance with one form of the present technology.

FIG. 90 is an enlarged anterior cross-sectional view of a plenum chamberin accordance with one form of the present technology.

FIG. 91 is an enlarged cross-sectional view of the plenum connectionregion.

FIG. 92 is an enlarged side cross-sectional view of a plenum chamber inaccordance with one form of the present technology.

FIG. 93 is a cross-sectional view of the connection portion and theframe connection region, wherein the plenum chamber and the frame arenot engaged.

FIG. 94 is a cross-sectional view of the connection portion and theframe connection region, wherein the plenum chamber and the frame are incontact but not fully engaged.

FIG. 95 is a cross-sectional view of the connection portion and theframe connection region, wherein the plenum chamber and the frame arenearly in full engagement with another such that the retention featureis deflected.

FIG. 96 is a cross-sectional view of the connection portion and theframe connection region, wherein the plenum chamber and the frame areengaged but separated such that the retention feature is deflected.

FIG. 97 is a cross-sectional view of the connection portion and theframe connection region, wherein the plenum chamber and the frame arefully engaged.

FIGS. 98 to 101 show various views of a frame according to an example ofthe present technology.

FIGS. 102 to 105 show various views of a plenum connection regionaccording to an example of the present technology.

FIG. 106 is a cross-sectional side view of a frame assembly and a cuffof a gas delivery tube connected to the frame assembly.

FIG. 107 is a cross-sectional side view showing a cuff of a gas deliverytube.

FIG. 108 is an enlarged cross-sectional view showing a portion of thecuff of FIG. 107.

FIG. 109 is a cross-sectional side view of a headgear clip for apositioning and stabilising system in accordance with one form of thepresent technology.

FIG. 110 is a rear view of a cushion assembly in accordance with oneform of the present technology.

FIG. 111 is a cross-sectional side view of a frame assembly includingstructure that segregates the incoming pressurised airflow path from theairflow path of outgoing exhaust air to a vent.

FIG. 112 is a cross-sectional side view of a headgear clip magneticallyand mechanically engaged with a magnet embedded in a lower arm of aframe assembly in accordance with one form of the present technology.

FIG. 113 is a cross-sectional view of a frame assembly in accordancewith one form of the present technology.

FIG. 114 is an enlarged cross-sectional view showing a portion of theframe assembly of FIG. 113.

FIGS. 115 to 121 show sequential steps for fitting a patient interfaceto a patient in accordance with one form of the present technology.

FIGS. 122 to 123 show sequential steps for removing a patient interfacefrom a patient in accordance with one form of the present technology.

FIGS. 124 to 126 show various steps for disassembling a patientinterface in accordance with one form of the present technology.

FIGS. 127 to 130 show various steps for reassembling a patient interfacein accordance with one form of the present technology.

FIGS. 131 to 137 show various views of a patient interface in accordancewith one form of the present technology.

DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

Treatment Systems

In one form, the present technology comprises apparatus for treating arespiratory disorder. The apparatus may comprise a flow generator orblower for supplying pressurised respiratory gas, such as air, to thepatient 1000 via an air circuit 4170 leading to a patient interface3000, as shown in FIG. 1 a.

Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

Nasal CPAP for OSA

In one form, the present technology comprises a method of treatingObstructive Sleep Apnea in a patient by applying nasal continuouspositive airway pressure to the patient.

Patient Interface 3000

Referring to FIG. 82, a non-invasive patient interface 3000 inaccordance with one aspect of the present technology comprises thefollowing functional aspects: a frame assembly 3001, a cushion assembly3002 (see FIG. 71) comprising a seal-forming structure 3100 (see FIGS.73 to 76, 80 and 81) and a plenum chamber 3200, and a positioning andstabilising structure 3300 (see FIG. 72). In some forms, a functionalaspect may be provided by one or more physical components. In someforms, one physical component may provide one or more functionalaspects. In use, the seal-forming structure 3100 is arranged to surroundan entrance to the airways of the patient 1000 so as to facilitate thesupply of air at positive pressure to the airways. The seal-formingstructure 3100 may also be commonly referred to as a cushion.

Referring to FIGS. 69, 71, and 72, the frame assembly 3001 functions asa central hub to which the short tube 4180, cushion assembly 3002 andpositioning and stabilising structure 3300 are connected, either in aremovable fashion or a more permanent fashion. The frame assembly 3001has a connection port 3600 (see FIG. 53) for connection to a short tube4180 of the air circuit 4170. In one example of the present technology,the frame assembly 3001 includes the sub-assemblies of the frame 3310,short tube 4180, and vent 3400.

The frame 3310 may also be commonly referred to as a frame chassis. Theframe 3310 releasably engages with the cushion assembly 3002 to providea 4 point connection to the positioning and stabilising structure 3300.The frame 3310 further comprises a multi-hole vent 3400 surrounding theconnection port 3600. The short tube 4180 comprises a non-swivel cuff10610 overmolded or otherwise connected to one end of the short tube4180. The cuff 10610 is overmolded or otherwise connected to theconnection port 3600 of the frame 3310 for fluid communication with theplenum chamber 3200 of the cushion assembly 3002.

In an example, the short tube 4180 is directly attached or otherwiseprovided to the frame 3310 without the use of an elbow or swivel elbow,which provides a more lightweight arrangement with one less part. In anexample, the short tube 4180 may provide sufficient flexibility toperform a similar function as an elbow or swivel elbow, to decouple tubetorque in certain directions.

In an example, the plenum chamber 3200 and the seal forming structure3100 are molded in one piece. In another example they are formed as twoor more separate components.

In FIG. 71, the cushion assembly 3002 may comprise a sealing region 251or sealing cuff, a side wall or side wall region 457, a retainingstructure 3242 and an attachment region 158. In an example, the cushionassembly 3002 may be formed from a flexible elastomer or rubber.Similarly, cushion assembly 3002 may comprise a sealing region 251, aside wall or side wall region 457 and a retaining structure 3242comprising retention features 3244, 3245. The retention features 3244,3245 may be in the form of a barb 3246 adapted to fit through respectiveframe connection regions 3312, 3313 positioned on the frame 3310 (e.g.,see FIGS. 98 and 100) for sealingly engaging the cushion assembly 3002to the frame 3310 in a releasable manner.

Seal-Forming Structure 3100

In one form of the present technology, the seal-forming structure 3100provides a sealing-forming surface, and may additionally provide acushioning function.

A seal-forming structure 3100 of the non-invasive patient interface 3000in accordance with the present technology may be constructed from asoft, flexible, resilient material such as silicone. The seal-formingstructure 3100 may form part of a sealed path for air from a PAP device4000 and is constructed and arranged to form a seal against thepatient's airways that surrounds both nares without being partiallylocated inside the nose. The seal-forming structure 3100 serves bothnares with a single orifice, e.g. a nasal cushion or nasal cradle. Thenasal cushion is a soft silicone cushion permanently over-molded onto aplastic clip component/retaining structure 3242. The cushion assembly3002 comprises the retaining structure 3242 for retaining a frame 3310over the walls of the plenum chamber 3200. The seal-forming structure3100 acts as the interface between the frame assembly 3001 and thepatient's face. The seal-forming structure 3100 provides the airchamber/plenum chamber 3200 and air seal around the patient's nose,necessary for delivery of the prescribed PAP (positive airway pressure)to the patient's nasal airway.

The seal-forming structure 3100 seals below the nasal bridge. This isintended to make the patient interface 3000 unobtrusive, yet comfortableand stable to avoid leak. The seal-forming structure 3100 has a modifieddual wall design (i.e. with an undercushion structure 265) for acomfortable seal. This is a dual walled cushion membrane design. A thinflexible outer membrane 260 inflates and conforms to the facial surface.The undercushion structure or inner membrane 265 provides the secondarystructural support to enhance the seal.

Referring to FIGS. 69, 71, and 80 to 83, in one form of the presenttechnology, a cushion assembly 3002 include a seal-forming structure3100 and a plenum connection region 3240 with a retaining structure3242. The cushion assembly 3002 may have a frusto-conical shape. Theretaining structure 3242 has a wide retention feature 3244 and a narrowretention feature 3245 for engagement with corresponding connectionregions 3312, 3313 on the frame 3310. The seal-forming structure 3100may comprise a sealing flange 3110 and a support flange 3120. Thesealing flange 3110 may comprise a relatively thin member with athickness of less than about 1 mm, for example about 0.25 mm to about0.45 mm. The support flange 3120 may be relatively thicker than thesealing flange 3110. The support flange 3120 is or includes aspring-like element and functions to support the sealing flange 3110from buckling in use. In use the sealing flange 3110 can readily respondto system pressure in the plenum chamber 3200 acting on its underside tourge it into tight sealing engagement with the patient's face. Theplenum chamber 3200 is made from a floppy material such as silicone.

Referring to FIG. 81, in one form of the present technology, a cushionassembly 3002 has a sealing flange 3110. The sealing flange 3110includes membrane 260-1 of the sealing region 251 and support flange3120 includes undercushion structure or backup band 265 of the sealingregion 251. The sealing flange 3110 extends around the perimeter 3210 ofthe plenum chamber 3200. The support flange 3120 is disposed between thesealing flange 3110 and the marginal edge 3220 of the plenum chamber3200, and extends at least part of the way around the perimeter 3210 ofthe plenum chamber 3200.

In one form of the present technology, the seal-forming structure 3100comprises a superior sealing portion 3102 and an inferior sealingportion 3104 (see FIG. 81). The superior sealing portion 3102 and theinferior sealing portion 3104 are, e.g., located adjacent one another,and one region may blend into the other.

Superior Sealing Portion 3102

Superior sealing portion 3102 is constructed and arranged to form a sealon a portion of the cartilaginous framework of the nose. In an example,superior sealing portion 3102 is constructed from a relatively thinmaterial, e.g., a flap, flange or membrane of material, e.g., athermoplastic elastomer, or a silicone rubber, and further, e.g., onethat readily bends or folds in response to light finger pressure whennot in use. Depending on the shape of the nose with which it is beingused, a relatively narrow width of superior sealing portion 3102 mayengage with nose ridge to form a seal. A relatively wider portion ofsuperior sealing portion 3102 may engage with the skin adjacent lateralnasal cartilage to form a seal.

The superior sealing portion 3102 is not designed to overlay the wholeof the nose. In an example, the superior sealing portion 3102 isconstructed and arranged, e.g., by being thin and flexible, to beadaptable to different heights of nose ridge. In this way, the range offaces that will be able to get a good seal is increased.

Furthermore, for a given face and nose, the flexibility of the superiorsealing portion 3102 means that a seal may be maintained should theplenum chamber 3200 may be moved, e.g., in response to movement of theshort tube 4180.

While the superior sealing portion 3102 is constructed so that it doesnot overlay the nasal bones in use, certain portions of the superiorsealing portion 3102 may overlay some part of the nasal bones on somefaces, depending on exactly how the patient interface 3000 is used andthe size and shape of the particular patient's face. In an alternativeform, the superior sealing portion 3102 is constructed and arranged toform a seal on the nasal bones in use.

Inferior Sealing Portion 3104

Inferior sealing portion 3104 is constructed and arranged to form sealon a portion of the upper lip of a patient 1000, and to direct at leastpart of a sealing force to the maxilla bone of the patient 1000. In use,part of the inferior sealing portion 3104 is located close to thesubalare and the alar crest point.

In one form, inferior sealing portion 3104 is configured to avoidexcessive pressure on the upper teeth or gums. In an example, theinferior sealing portion 3104 does not extend along bone (e.g., frontalprocess of maxilla) superiorly to the alar crest point, however itshould be appreciated that in other examples it might.

Inferior sealing portion 3104 may be constructed from a single,relatively thicker flap, rim or flange of material, e.g. a siliconerubber, or thermoplastic elastomer, e.g. with a thickness of about 1 mmto 2 mm. In one form, inferior sealing portion 3104 may be constructedfrom a dual flap, rim or flange, for example one being relatively thinand the other being relatively thick. Alternatively, inferior sealingportion 3104 may be constructed from a gel-filled bladder.

“W” Shaped Region

FIG. 75 shows a cushion assembly 3002 according to another example ofthe present technology. In this example, the cushion assembly 3002includes a general “W” shape in the top lip region 255, i.e., general“W” shape along the outer (inferior) edge 260(o) of the membrane 260-2in the top lip region 255.

In FIG. 76, in another example, the cushion assembly 3002 comprises aseal-forming structure 3100 having a general “W” shape along both theinner (superior) edge 260(i) of the membrane 260-3 and the outer(inferior) edge 260(o) of the membrane 260-3 in the top lip region 255.In one form, the “W” portion of the top lip region 255 is constructedand arranged so that a middle portion of the “W” may rest on thesubnasale or columella in use, in the event of the seal-formingstructure 3100 shifting upwards (superiorly) in use, leaving clearanceor space (which is between an inner edge of the undercushion 265 and aninner surface of the plenum chamber 3200) under the nostrils or aroundthe respective left and right subalare.

In another example, as shown in FIG. 110, the cushion assembly 3002 mayinclude a general “W” shape along the inner (superior) edge 260(i) ofthe membrane 260-3 and a general flat or planer shape along the outer(inferior) edge 260(o) of the membrane 260-3 in the top lip region 255.In an example, the general flat or planar outer edge or substantiallyflat lower wall 260(o) in FIG. 110 may alleviate pressure on thepatient's upper lip.

In an example, a portion of the sealing portion(s) 3102, 3104 may have aquestion-mark shaped, sickle shaped, or c-shaped cross-section. Thequestion-mark shaped, sickle shaped, or c-shaped cross-section mayprovide the sealing portion 3102, 3104 with greater range of movement orflexibility towards the patient's face in use. In the illustratedexample, the question-mark shaped, sickle shaped, or c-shapedcross-section is provided to a lower portion of the undercushion 265and/or a side wall region 457 (see FIG. 71), which provides a spacebelow the lower portion of the undercushion 265 and adjacent the sidewall region 457. For example, the lower portion of the undercushion 265is radially offset towards the outside of the side wall region 457. Itshould be appreciated that such cross-section may be provided around theentire perimeter of the seal-forming structure 3100 or may only beprovided in selected regions of the seal-forming structure 3100, e.g.,only in the top lip region 255. Also, the size and/or configuration ofsuch cross-section may vary in selected regions.

In the illustrated example of FIGS. 73 and 74, D6 is about 40 mm to 50mm (e.g., about 42 mm), D7 is about 55 mm to 75 mm (e.g., about 68 mm),and D8 is about 20 mm to 30 mm (e.g., about 24 mm). Although specificdimensions are provided, it is to be understood that these dimensionsare merely exemplary and other dimensions are possible depending onapplication. For example, the exemplary dimensions may vary by +/−10% to20% or more or less depending on application (see FIG. 75).

Sealing Region 251

Referring to FIG. 73, in accordance with another form of the presenttechnology, seal forming structure 3100 comprises sealing region 251.Sealing region 251 may be adapted to interface with the patient 1000 andform a seal with the patient's airways. Sealing region 251 may include anose ridge region 252, sides of the nose region 253, corners of the noseregion 254 and top lip region 255. Sealing region 251 may comprise amembrane or flap type seal 260. In an example, the inner edge of themembrane 260-1 may include a bead 260-1, e.g., to prevent tearing,enhance sealing along the edge. Sealing region 251 may further comprisean undercushion structure or backup band 265, extending around part ofor the entire perimeter of the sealing region 251. A further aspect ofthe present technology is a seal-forming structure 3100 for a mask 3000that seals at its upper extent in a region of the nose that is generallyabove the tip of the nose, and extends across the alar or flares of thepatient's nose.

In an example, the sealing region 251 may be preformed or otherwisepre-shaped so as to conform to that patient's facial topography.

Sealing Along Nasal Ridge

One aspect of the present technology relates to sealing of the sealingregion 251 in the nose ridge region 252. In an example, the sealingregion 251 in the nose ridge region 252 is adapted to engage along thepatient's nasal ridge between the pronasale and sellion, and along thenasal cartilage region of the nasal ridge and below or inferior to thenasal bone. That is, the patient interface 3000 is constructed to have aseal-forming structure 3100 that is substantially on at least part ofthe cartilaginous framework of the patient's nose and not on the nasalbone, i.e., seal along nasal ridge without contacting nasal bridge/skinon the nasal bone.

For example, the sealing region 251 is adapted to be positioned and sealat-its upper extent in a region of the nose that is generally above thetip of the nose (i.e., above the pronasale), and extends across the alaror flares of the patient's nose, e.g., not extending over or across thebone of the patient's nose.

In an example, the sealing region 251 is positioned at its upper extentin a region of the nose that is generally close to the junction betweenbone and cartilage on a range of people with larger noses, and avoidsimpinging on the sight of patients 1000 with smaller noses.

Nose Ridge Region 252

Referring to FIG. 74, the nose ridge region 252 may be adapted to engagewith a nose ridge of a patient 1000. In an example, the nose ridgeregion 252 may be shaped or preformed to accommodate a patient's noseridge, the nose ridge region 252 may be lower (i.e., closer to theattachment region 158) than the sides of the nose region 253. Nose ridgeregion 252 may comprise a membrane 260-1 for sealing without anundercushion or backup band. In an example, such an arrangement preventsexcess pressure on the sensitive nose ridge region 252. In an example,the membrane 260-1 at the nose ridge region 252 may be relatively longerthat the membrane 260-1 in other regions of the sealing region 251, forexample the top lip region 255. The membrane 260-1 in the nose ridgeregion 252 may be, for example, about 2 mm to 5 mm in length. In anexample, the membrane 260-1 in the nose ridge region 252 may be about2-4 mm in length. In an example, the membrane 260-1 in the nose ridgeregion 252 may be about 3 mm in length.

Sides of the Nose Region 253

Referring to FIG. 74, sides of the nose region 253 may be adapted toengage with the sides of a patient's nose. In an example, sides of thenose region 253 may be preformed to accommodate the sides of thepatient's nose and potentially their cheeks. Sides of the nose region253 extends from the apex of the seal-forming structure 3100 at noseridge region 252 to the corners of the nose region 254. The sides of thenose region 253 slopes upwardly from the nose ridge region 252 to thecorners of the nose region 254. Sides of the nose region 253 maycomprise a membrane 260-1 for sealing without an undercushion or backupband. In an example, such arrangement prevents excess pressure on thesides of the patient's nose or alar or flares. Excess pressure on theseregions may cause the cartilage of the nose to collapse inwardly towardsthe septum, thereby occluding or partially occluding the patient'sairway.

Corners of the Nose Region 254

Referring to FIG. 74, corners of the nose region 254 may be adapted toform a seal with the comers of the patient's nose. The corners of thenose region 254 having an apex or point, being the maximum height of thesealing region 251. This height is to ensure that the most force isapplied to the sealing region 251 in the corners of the nose region 254,as this is a boney region of the face and is therefore less sensitive topressure. Furthermore, this region of the patient's face is particularlydifficult to seal on as the geometry of the face in this region is quitecomplex, so the greater the force applied to the seal in this region,the more likely a seal will form. In addition, since lower sealingforces are required on the nose ridge region 252 and the sides of thenose region 253 (for comfort and to avoid occlusion), the sealing region251 must be anchored at the corners of the nose region 254. Corners ofthe nose region 254 may comprise a membrane or membrane seal 260 and anundercushion structure or backup band 265. The use of both a membrane260-1 and an undercushion structure 265 may ensure a higher sealingforce in the nose region 254. In an example, the membrane 260-1 may havea thickness about 0.1-0.5 mm, for example about 0.3 mm. In an example,the undercushion structure 265 may have a thickness of about 0.3 mm to 2mm.

Top Lip Region 255

Referring to FIG. 74, top lip region 255 may be adapted to engage thesurface between the patient's upper lip and base of the nose. In anexample, top lip region 255 may have a relatively shorter membranelength than the nose ridge region 252, for example a length of about 0.5mm to 2.5 mm, e.g., about 1.5 mm to 2.5 mm. In an example, this shortermembrane length may be advantageous as some patient's only have a smallspace between their upper lip and the base of their nose. Top lip region255 may have a membrane seal 260 and an undercushion structure or backupband 265. The use of both a membrane 260-1 and an undercushion structure265 may ensure a higher sealing force in the top lip region 255. In anexample, the membrane 260-1 may have a thickness about 0.1-0.5 mm, forexample about 0.3 mm. In an example, the undercushion structure 265 mayhave a thickness of about 0.3 mm to 2 mm, for example about 1.5 mm. Inan example, the thickness of the undercushion structure 265 may varyalong the length of the top lip region 255, for example from about 0.3mm at the corners of the nose region 254, to about 1.2 mm at the centreof the top lip region 255.

Seal

Use of the undercushion structure 265 or back-up band enables themembrane 260-1 or facial flap to be made considerably thinner than if asingle unsupported flap were used. This is highly advantageous in that athinner flap is in turn more flexible, so as to feel softer and morecomfortable and more readily conform to irregularities in the facialcontour. It also permits the flap to more readily respond to systempressure in the plenum chamber 3200 acting on its underside to urge itinto tight sealing engagement with the patient's face.

As noted above, the patient interface is constructed to have aseal-forming region that is substantially on the cartilaginous frameworkon the nose (i.e., not on the nasal bone), and which does not block thenose. In an example, this may be achieved by providing a compressionseal (e.g., using an undercushion structure 265) along the patient'supper lip (e.g., inferior sealing portion 3104) and not on the patient'snose. Seal on the patient's nose (e.g., superior sealing portion 3102)may be achieved by tension in the membrane 260-1 and/or a pneumaticseal.

In one example, the undercushion structure or backup band 265 is onlyprovided in the top lip region 255 and the corners of the nose region254 of the seal-forming structure 3100. That is, the sealing region 251includes a single layer or membrane 260-1 only structure in the noseridge region 252 and sides of the nose region 253 and the sealing region251 includes a dual layer or membrane 260-1 and undercushion structure265 in the top lip region 255 and corners of the nose region 254. Thedual layer structure provides a compression seal along the top lipregion 255 and corners of the nose region 254. In contrast, the noseridge region 252 and sides of the nose region 253 uses tension in themembrane 260-1 (edge of the membrane 260-1 stretched into sealingengagement due to tension applied to the membrane 260-1) and/or pressurein the plenum chamber 3200 acting on the membrane 260-1 (pneumatic seal)to provide a seal. The single layer is also provided in the nose ridgeregion 252 and sides of the nose region 253 to provide a softer and moreflexible seal that avoids any potential for blocking the patient's nose,i.e., prevents excess pressure on the sides of the patient's nose oralar or flares which may cause the cartilage to collapse inwardly andpotentially at least partially occlude the patient's airway.

Thus, the cushion assembly 3002 according to an example of the presenttechnology provides different sealing mechanisms in different portionsof the seal-forming structure 3100. For example, the cushion assembly3002 may provide one mechanism of sealing in the superior portion of theseal-forming structure 3100 (e.g., sealing by tension in the membrane260-1 and/or a pneumatic seal) and a different mechanism of sealing inthe inferior portion of the seal-forming structure 3100 (e.g.,compression seal). In the illustrated example, the cushion assembly 3002provides a compression seal via a dual layer or membrane 260-1 andundercushion structure 265. However, it should be appreciated that thecompression seal may be provided by alternative structures, e.g.,gel-filled or foam-filled pocket, thicker single wall (e.g., about 0.8mm to 1.2 mm thick silicone).

When the cushion assembly 3002 is engaged with the patient's face andunder pressure or inflated in use, i.e., supply of air at positivepressure being applied to the cushion assembly 3002, a width or contactarea 280 of the sealing portion 3102, 3104 is engaged with the patient'sface in use. The width or contact area includes an inner edge 280(i),for example, along the edge of an orifice 275 (see FIG. 73) and an outeredge 280(o). A relatively narrow width of superior sealing portion 3102may engage with the nose ridge to form a seal, e.g., depending on theshape of the nose with which it is being used. A relatively widerportion of superior sealing portion 3102 may engage with the skinadjacent lateral nasal cartilage to form a seal. In the inferior sealingportion 3104, substantially the entire width of the inferior sealingportion 3104 may engage the skin along the corners of the nose region254 and top lip region 255 to form a seal. Thus, the width or contactarea of the sealing portion 3102, 3104 engaged with the patient's facein use may vary around the perimeter of the cushion assembly 3002 toform a seal.

Sealing Flap

In an example, as shown in FIGS. 73 and 74, each sides of the noseregion 253 of the sealing region 251 includes a portion 270, e.g., awing or sealing flap, that protrudes from the edge of the membrane 260-1along its inner perimeter. Each sealing flap 270 is adapted to form aseal on the region adjacent the junction between the nasal greater alarcartilage and the lateral nasal cartilage of a patient's nose (alsoreferred to as the alar crease). The exact location of the sealing flap270 on a face in use may vary depending on the size and shape of thenose with which it is being used.

As illustrated, each sealing flap 270 is at least partially angled orpre-biased outwardly away from the plenum chamber 3200 of theseal-forming structure 3100. When engaged with the patient's nose, thesealing flaps 270 are deflected towards the plenum chamber 3200 whichprovides a bias for sealing in the junction noted above. That is, theshape, flexibility, and pre-bias of the sealing flaps 270 allows theflaps 270 to accommodate changes in curvature or contour in thisjunction (e.g., which tend to continually vary when the nasal alar or“flare” in use) so as to maintain seal and prevent leaks in use.

Referring to FIGS. 73 and 74, in an example, the sealing flange 3110(including membrane 260-1 and sealing flap 270) defines a generallyT-shaped orifice. The edge of the membrane 260-1 along its innerperimeter along with the edge of each sealing flap 270 along its innerperimeter, cooperate to define an orifice 275 into the plenum chamber3200. In an example, such orifice 275 includes a general T-shapeincluding an upper orifice portion 275(1) (along vertical axis v asviewed in FIG. 73) and a lower orifice portion 275(2) (along horizontalaxis h as viewed in FIG. 73) that extends generally transverse to theupper orifice portion 275(1).

The sealing flap 270 of the sides of the nose region 253 changes thecurvature and/or angle of the edge defining the orifice 275, i.e., edgeof the orifice 275 curves upwardly and outwardly away from the plenumchamber 3200 at least along the sealing flap 270.

Curvature of the Cushion

The curvature of the seal-forming structure 3100 may vary along thepatient contacting surface of the membrane 260-1 in different regions ofthe seal-forming structure 3100, e.g., to facilitate sealing indifferent regions of the patient's face.

For example, as shown in FIG. 73, the nose ridge region 252 and the toplip region 255 each include at least a portion that is locallysaddle-shaped in curvature, e.g., curves up in one direction and curvesdown in a different direction. It should be appreciated that theabove-noted shapes of curvature are approximate shapes and should not belimited to strict mathematical definitions of such shapes. In addition,it should be appreciated that regions may include similar curvatureshapes, but the magnitudes of such curvature may be different. Forexample, the nose ridge region 252 and the top lip region 255 may bothinclude at least a portion that is locally saddle-shaped, however themagnitude of curvature in one and/or both principle directions of suchsaddle-shape may be different in each region.

Aperture

In an example, where a single mask should be used to fit about 85% ofthe female population, the undercushion aperture width (e.g., indicatedat uw in FIG. 76 for example) is about 36 mm to about 42 mm, or about 38mm to about 40 mm. In an example, where a single mask should be used tofit about 85% of the male population, the undercushion aperture width isabout 40 mm to about 46 mm, or about 42 mm to about 44 mm. In one form,to account for nose width variations of various ethnicities, to fit upto 95% of an average population, an undercushion aperture width is about50 mm to about 56 mm, or about 52 mm to about 54 mm.

In an example, where a single mask should be used to fit about 85% ofthe female population, the membrane aperture width (e.g., indicated atmw in FIG. 76 for example) is about 23 mm to about 29 mm, or about 25 mmto about 27 mm. In an example, where a single mask should be used to fitabout 85% of the male population, the membrane aperture width is about39 mm to about 45 mm, or about 41 mm to about 43 mm. In one form, toaccount for nose width variations of various ethnicities, to fit up to95% of an average population, a membrane aperture width is about 49 mmto about 55 mm, or about 51 mm to about 53 mm.

Side Wall Region 457

Referring to FIG. 71, side wall region 457 may extend between sealingregion 251 and attachment region 158 of the cushion assembly 3002. Sidewall region 457 may be generally conical, that is, it may have a firstdiameter at proximate attachment region 158 and a second diameterproximate sealing region 251, with the first diameter being less thanthe second diameter. Side wall region 457 may have a thickness of about1.5-5 mm, e.g., about 1.5-3 mm, e.g., about 2 mm. Such a thickness mayprovide some support to the sealing region 251 to ensure that theseal-forming structure 3100 does not collapse from headgear tension whenin use.

Thinner Wall Section

Referring to FIG. 71, the side wall region 457 between the sealingregion 251 and the attachment region 158 includes an area adjacent thetop lip region 255 of the sealing region 251 that includes a thicknessthat is less than corresponding thicknesses adjacent the nose ridge,sides of the nose, and corners of the nose regions of the sealing region251. That is, the area includes a thinner walled cross-section adjacentthe top lip region 255 of the sealing region 251. Such area of thinnercross-section lessens the force provided by the sealing region 251 alongthis section of the top lip region 255. For example, such area providesless pressure along the top lip region 255 than the corners of the noseregion 254 (i.e., stiffer along the corners of the nose region 254 thanthe top lip region 255 thereby giving rise or effecting relativelygreater pressure along the corners of the nose region 254 (along thecorners of the lip adjacent the alars), in order to avoid excessivepressure on the columella or septum of the patient's nose which is amore sensitive region of the patient's nose.

FIG. 74 depicts the nose ridge region 252 and the top lip region 255showing the single layer or membrane 260-1 only structure in the noseridge region 252 and the dual layer or membrane 260-1 and undercushionstructure 265 in the top lip region 255. The thinner cross-section areain the side wall region 457 adjacent the top lip region 255, forexample, avoids excessive pressure on the columella or septum.

Plenum Chamber 3200

Plenum chamber 3200 in accordance with an aspect of one form of thepresent technology functions to allow air flow between the patient'snares and the supply of air from PAP device 4000 via a short tube 4180.In this way the plenum chamber 3200 may function alternatively as aninlet manifold during an inhalatory portion of a breathing cycle, and/oran exhaust manifold during an exhalatory portion of a breathing cycle.

The plenum chamber 3200 includes a retaining structure 3242 and a plenumconnection region 3240.

Plenum chamber 3200 is formed in part by a side wall. In one form, theside wall includes side wall region 457 of sealing region 251. Theplenum chamber 3200 has a perimeter 3210 that is shaped to conformgenerally to the surface contour of the face of an average person (e.g.,see FIGS. 73 to 76). In use, a marginal edge 3220 of the plenum chamber3200 is positioned in close proximity to an adjacent surface of thepatient's face (see FIGS. 80 and 81). Actual contact with the patient'sface is provided by the seal-forming structure 3100. In an example, theseal-forming structure 3100 extends in use about the entire perimeter3210 of the plenum chamber 3200. In an example, the plenum chamber 3200is adapted to receive a portion of the patient's nose including thepronasale, e.g., the plenum chamber 3200 forms over and surrounds aportion of the cartilaginous framework of the nose including thepronasale.

In an example, the walls of the plenum chamber 3200 are flexible, orsemi-rigid. In an example, plenum chamber 3200 does not include a rigidframe or shell. In an example, the walls of the plenum chamber 3200 arenot rigid, and, e.g., the walls of the plenum chamber 3200 are notfloppy. In certain forms, flexibility of the walls of the plenum chamber3200 assists to decouple a tube drag force from disrupting a seal.

In one form, the walls of the plenum chamber 3200 are molded from asilicone rubber. In an example, the walls of the plenum chamber 3200 areconstructed from a silicone rubber with a Type A indentation hardness ofabout 35 to about 40, and with a thickness in the range of about 2 mm toabout 4 mm. In certain forms of the present technology, the plenumchamber 3200 may have different thicknesses in different regions.

Plenum chamber 3200 may be constructed from an elastomeric material.

Plenum chamber 3200, in accordance with another aspect of one form ofthe present technology, provides a cushioning function between theseal-forming structure 3100 and the positioning and stabilisingstructure 3300.

Whilst in one form of the plenum chamber 3200, the inlet/outlet manifoldand cushioning functions are performed by the same physical component,in an alternative form of the present technology, they are formed by twoor more components.

The seal-forming structure 3100 and the plenum chamber 3200 may beformed, e.g. molded, as a single and unitary component.

The marginal edge 3220 of the plenum chamber 3200 forms a connectionwith seal-forming structure 3100. The marginal edge 3220 may beconstructed from a silicone rubber, e.g., with a Type A indentationhardness in the range of about 35 to about 45. However, a wider range ispossible if the thickness of the marginal edge 3220 is adjustedaccordingly to obtain a similar level of force.

In one form, the plenum chamber 3200 may further comprise a sealing lip3250 (see FIG. 80). Sealing lip 3250 may be constructed from a flexibleresilient material, e.g. silicone rubber with a type A hardness in arange of about 30 to about 50, forming a relatively soft component.Sealing lip 3250 may be located on or formed as part of an interiorsurface or interior periphery of plenum chamber 3200, or an entireinterior peripheral region of plenum chamber 3200. However, it is alsoenvisioned that the sealing lip 3250 may be disposed about an exteriorsurface or exterior periphery of the plenum chamber 3200, or an entireexterior peripheral region of plenum chamber 3200. Sealing lip 3250 mayform a pneumatic seal between plenum chamber 3200 and frame 3310, aswill be described in greater detail below. Sealing lip 3250 and plenumchamber 3200 may also comprise one piece.

Other patient interface devices form the pneumatic seal between theplenum chamber and frame using a compression seal to compress the plenumchamber made from a resiliently deformable material such as silicone toengage the plenum chamber to the frame and create the pneumatic seal atthe same time. In contrast, one example of the present technology, formsa pneumatic seal when the plenum chamber 3200 is initially secured tothe frame 3310 by interference from the sealing lip 3250 deflectingagainst the frame 3310. When pressure within the plenum chamber 3200 isincreased above atmospheric pressure for treating breathing disorders,the pneumatic seal is strengthened and increases the sealing forcebecause the sealing lip 3250 is urged with greater force against theframe 3310. The air pressure within the seal-forming structure3100/plenum chamber 3200 of these other patient interface devices doesnot influence the sealing force between the seal-forming structure 3100and the frame 3310. Also, these other patient interface devices have acushion with side walls for engagement with the frame and sealing lipsthat are floppy because they readily conform to finger pressure, are notrigid, and are able to be stretched or bent elastically with littleeffort. In particular, due to the size and aspect ratio of a nasalcushion being relatively large, this contributes to the floppiness ofthe cushion. The side walls for frame engagement are so floppy thatopposing sides of the cushion are able to be pinched together andbrought into contact with each other with very little finger force. Thisease of deformation of the side walls for frame engagement may be theprimary source of difficulty for patients with arthritic hands toquickly connect the cushion to the frame in these other patientinterfaces. It should also be understood that by forming the plenumchamber 3200 features discussed above with sufficient stiffness it maybe possible to improve the stability of the seal made by theseal-forming structure. Furthermore, it may be possible to vary thethickness of the plenum chamber 3200 such that it becomes thinner from aplenum connection region 3240 to the seal-forming structure 3100. In oneexample of the present technology, the plenum chamber 3200 may be about2 to 3 mm thick near or at the plenum connection region 3240, 1 mm thickat a point between the plenum connection region 3240 and theseal-forming structure 3100, and 0.75 mm thick near or at theseal-forming structure 3100. Forming the plenum chamber 3200 with thesefeatures may be accomplished by injection molding manufacturing. Thisgradual reduction in thickness of the plenum chamber 3200 enablesgreater deformability of silicone material closer to the contact area ofthe sealing portions 3102, 3104 to enhance patient comfort and reducethe likelihood of seal disruption.

Some nasal patient interfaces have an assembled order of (i), plenumchamber, (ii) headgear connection, and (iii) seal-forming structure. Incontrast, one example of the patient interface 3000 of the presenttechnology has an assembled order of (i) headgear connection, (ii)plenum chamber, and (iii) seal-forming structure. This difference inarrangement means that headgear tension does not cause deformation ofthe plenum chamber 3200 and the seal-forming structure 3100 which maylead to disruption of sealing forces.

Frame 3310

The frame 3310 may be made from a thermoplastic material includingTritan™ manufactured by Eastman Chemical Company, Grilamid™ manufacturedby EMS-Chemie AG, or Rilsan™ G170 manufactured by Arkema, Inc.Preferably, a water clear transparent thermoplastic is used for theframe 3310, rather than a translucent or opaque material. The provides aclear under eye frame 3310 offering unimpeded vision and unobtrusivenessfor the patient 1000 as well as stability for the patient interface3000. In another example, the frame 3310 may be frosted on one or bothsides.

In one example of the technology, the frame 3310 may be formed frompolypropylene. In other examples, the frame 3310 may be formed fromnylon or polyester. The frame 3310 is overmolded onto the short tubecuff 10610, while the rotating swivel end 4190 joins to the short tube4180 via interference press fit. The flexible and extensiblecharacteristics of the short tube 4180 together with the 360° rotatingswivel end piece 4190 is designed to mechanically decouple the mask 3000from the additional gas delivery tube 4178 of the air circuit 4170.

In another example of the technology, the frame 3310 may be made in onesize but the plenum chamber 3200 and seal-forming structure 3100 may bemade in multiple sizes that are attachable to the single frame 3310 bycommonly sized connections features as described herein. In an example,the seal-forming structure may be made in three sizes but use the sameretaining structure attachable to the frame. However, it should beappreciated that more or less sizes of the seal-forming structure arepossible.

In an example of the technology the frame 3310 may be molded without anyundercuts such that it may be molded and then removed from the mold toolwithout flexing.

Referring to FIGS. 59 to 63, in another example of the presenttechnology, the seal-forming portion 3100 of the patient interface 3000is held in sealing position via a four-point connection to a positioningand stabilising structure 3300. The frame 3310 provides two pairs ofopposing arms: two upper arms 10320 and two lower arms 10330. The upperarms 10320 provide an opposing pair of upper headgear connection points10325. The lower arms 10330 provide an opposing pair of lower headgearconnection points 10331. In one form, the lower headgear connectionpoint 10331 has a cylindrical shape which is integrally formed with thelower arm 10330.

As illustrated, the frame 3310 includes a main body in the form of aring member or ring portion 10315 defining the connection port 3600 anda joining member or joining portion 10316 extending posteriorly from thering member 10315 at an upper position on the ring member 10315, e.g.,see FIGS. 59-61. The lower arms 10330 extend from lower arm connectionpoints 10317 radially positioned on the ring member 10315. The upperarms 10320 extend from an upper arm connection point 10305 (alsoreferred to as a top frame connection point) at a distal end of thejoining member 10316 such that the lower arm connection points 10317 arein a position anterior from the upper arm connection point 10305.

In an example, as best shown in FIG. 60, the upper arm connection point10305 is at an upper most position on the ring member 10315, and thelower arm connection points 10317 are positioned about 80° to about160°, e.g., about 90°, from the upper arm connection point 10305.

In an example, the upper arms 10320 and their upper headgear connectionpoints 10325 are positioned and oriented such that they direct theforce/tension provided by the upper headgear straps 10230 into anupwards force vector. The upwards force vector provides a force to allowthe seal-forming structure 3100 of the patient interface 3000 tooptimally seal on the upper lip and the cartilaginous framework. Theupper headgear straps 10230 direct an upwards force vector on the topportion of the frame 3310 in a manner that translates this force ontothe seal-forming structure 3100 to a top nose ridge region 252 of thesealing region 251. The upper arms 10320 arch or curve towards anupwardly direction from the top frame connection point 10305.

In an example, the lower arms 10330 and their lower headgear connectionpoints 10331 are positioned and oriented such that they direct the lowerheadgear straps 10220 into a downwards force vector that provides acounteractive force to resist ride up of the nasal mask 3000 and anyseal disruptive forces in the upwards direction thereby increasingstability. The counteractive force may also provide a downwards forcevector, which increases stability in the tube up configurations of theshort tube 4180 of the patient interface 3000, in use.

As noted above, the upper arm connection point 10305 and the lower armconnection points 10317 are spaced apart at a predetermined distance,i.e., upper arm connection point 10305 set back or posterior from thelower arm connection points 10317, which provides a maximum tiltingrange for the frame 3310 relative to the patient's face. Such offsetspacing defines a moment arm MA providing the maximum tilting range(e.g., see FIG. 111). This offset spacing is provided in part by the useof joining portion 10316.

FIG. 111 shows the moment arm MA between the upper arm connection point10305 and the lower arm connection points 10317, with the center ofrotation or pivot point PP at a lower side of the frame. In an example,the pivot point PP may be lower and/or closer to the patient's face thanillustrated when the seal-forming structure 3100 is attached andcontacting the patient's face. The pivot point/center of rotation PP ofthe frame relative to the patient's face is moved lower down due to thesingle and central location of the upper arm connection point 10305 onthe frame 3310. This creates tilt when the upper headgear straps 10230are adjusted/tightened, to ensure the patient interface 3000 fits wellon the patient. The frame 3310 segregates the upper arms 10320 from thelower arms 10330 so that the upper straps 10230 may have a differenttension to the lower straps 10220, depending on the patient's face anddesired fit.

The upper headgear straps 10230 are connected to the frame 3310 via theupper arms 10320 at a single and central upper point 10305, thereforethe upper headgear vector UV when headgear tension is applied issubstantially parallel to the Frankfort horizontal direction. Thisminimizes the mask 3000 from riding up or riding down, and creates goodstability. That is, the upper arms 10320 are releasably engageable withupper headgear straps 10230 and the upper arms 10320 direct a tensionvector of the upper headgear straps 10230 in a direction substantiallyparallel to the Frankfort horizontal direction and avoid extendingacross the patient's ears. In an example, the lower arms 10330 provide alower headgear vector LV when headgear tension is applied that issubstantially parallel to the Frankfort horizontal direction.

FIG. 111 shows the maximum tilting range aspect and its relationshipwith the headgear force or tension vectors. When the upper headgearstraps 10230 are tightened, the upper headgear straps 10230 will pullthe upper arms 10320 and cause the patient interface 3000 to tilt andfit and/or seal better such that the cross-section of the anteriorsurface of the frame 3310 is substantially perpendicular to theFrankfort horizontal direction. This would prevent the mask 3000 ridingup or riding down relative to the patient's face.

Also, in an example, the upper arms 10320 include sufficientrigidity/stiffness so that headgear tension from the upper headgearstraps 10230 do not cause the upper arms 10320 to substantially deformor change their shape or profile. For example, the upper arms 10320 aresufficiently rigid or stiff to prevent pivoting relative to the frame3310 and prevent the upper arms 10320 from straightening out orflattening when headgear tension is applied. Rather, the force fromheadgear tension from tightening the upper headgear straps 10230 istranslated to the upper arm connection point 10305 to cause the ringmember 10315 of the frame 3310 to tilt about the pivot point/center ofrotation PP as noted above so that the cushion assembly 3002 provides anoptimal seal.

WO 2009/108995 discloses an example of a mask system including a shroudwith upper and lower arms providing upper and lower headgear connectors.In contrast to the frame 3310 according to an example of the presenttechnology, the center of rotation/tilting in WO 2009/108995 is locatedin the same coronal plane as the upper headgear connection point and thelower headgear connection point, i.e., WO 2009/108995 does not haveoffset upper and lower headgear connection points. That is, the frame3310 according to an example of the present technology provides a centerof rotation/tilting that is not located in the same coronal plane as theupper and lower headgear connection points. Also, the patient interface3000 according to an example of the present technology provides a nasalinterface or nasal mask which provides a smaller facial footprint thanfull-face masks such as that disclosed in WO 2009/108995, and whichprovides different vectors and tilting when adjusting headgear tension.

The joining member 10316 which joins the upper arms 10320 to the ringmember 10315 at a single point, i.e., upper arm connection point 10305,on the ring member 10315 is relatively stiff so that the force issubstantially completely translated, and also is strong enough toprevent breakage at the joining member 10316. Stiffness may be achievedby either structural elements (reinforcement ribs) or materialproperties (thicker or a more rigid material), or a combination of both.

In one example of the present technology, the upper arms 10320 of theframe 3310 are symmetrical. The upper arms 10320 extend from the frame3310 at the top frame connection point 10305 and terminate substantiallyin a middle position between the patient's eyes and ears. The upper arms10320 extend over the cheeks of a patient in use and have a curvedprofile to fit the profile of a patient's face so as to minimizeobstruction. The upper arms 10320 extend outwardly from the patient'sface so as to minimize contact between the upper arms 10320 and thepatient's face to avoid discomfort. In a further example, the upper arms10320 extend between 80 mm to 100 mm from the top frame connection point10305 of the frame 3310.

The lower arms 10330 extend outwardly from the frame 3310 at an angle ina direction approximately parallel to the second curved section 10311 ofthe upper arm 10320 in the transverse plane (see FIGS. 62 and 63). Thelower arms 10330 have some curvature in the sagittal plane and thedirection of curvature is in a downwardly direction. The lower arms10330 have a curved profile to fit a patient's face in use so as tominimize obtrusiveness and have some close conformity with the patient'sface.

The lower arms 10330 are approximately half the length of the upper arms10320. The lower arms 10330 extend to a point substantially on thebottom of a patient's cheeks in use. In a further example, the lowerarms 10330 extend between 20 mm to 40 mm from the bottom of theconnection portion 3600 of the frame 3310.

The Shape of Arms for the Frame 3310

Referring to FIGS. 56-61, initially from the top frame connection point10305, the upper arms 10320 sweep in a downwardly arcuate directionapproximately following the curvature of the connection port 3600. Anelongate void 10306 extending from the frame 3310 separates the upperarms 10320 from the lower arms 10330. This decouples the upper arms10320 from the lower arms 10330, and therefore each of the four arms10320, 10330 of the frame 3310 should minimally affect the other arms10320, 10330. In contrast, a Y-shaped or branched arm member wouldgenerally easily translate movement between an upper headgear point to alower headgear point.

Each upper arm 10320 has a first curved section 10307 extending from thetop frame connection point 10305 to a first bend 10308. The profile ofan inner surface of the first curved section 10307 is curved tocorrespond to a profile on the outer surface of the cushion assembly3002. A bottom edge of the first curved section 10307 and an outerradial edge of the connection port 3600 and upper edge of a lower arm10330 define the elongate void 10306. A substantially straight section10309 extends from the first bend 10308 to a second bend 10310.

A second curved section 10311 extends from the second bend 10310 untilthe distal end of the upper arm 10320. The direction of curvature forthe second curved section 10311 is in an upwardly direction. The secondcurved section 10311 of the upper arms 10320 provide for additionalsupport and rigidity. The second curved section 10311 extends towardsthe upper headgear connection points 10325 to a sharp or smoothtransition in width to form a thinner distal end 10323 of the upper arm10320.

The distal end 10323 of the upper arm 10320 is an enlarged portion ofthe upper arm 10320 which has the upper headgear connection point 10325in the form of an elongate slot 10325 to receive the upper headgearstrap 10230. The distal end 10323 is angled upwards from the secondcurved section 10311 to position the upper headgear connection points10325 substantially between the eyes and ears of a patient 1000 in use.The inner surface profile of the distal end 10323 conforms to thepatient's face profile in use, in the upper cheek region andsubstantially between the eyes and ears. The longitudinal axis of theelongate slot 10325 is oriented to be substantially perpendicular to thelongitudinal axis of the upper arm 10320 (e.g., the longitudinal axis ofthe slot 10325 is substantially perpendicular to the longitudinal axisof the second curved section 10311 of the upper arm 10320 as viewed inFIG. 61 for example) and is sized to receive an upper headgear strap10230 passing therethrough.

The upper arm 10320 has curvature in the sagittal, coronal andtransverse planes because it has a three dimensional shape and isnon-planar. The shape of the upper arm 10320 is intended to follow thepatient's cheek, frames the patient's face and be out of the patient'sline of sight. The profile of the upper arm 10320 from above shows thatan inner surface of the straight section 10309 is curved such that itconforms to the curvature of a patient's face in use, proximal to thecheek region (see FIG. 58). In addition, the upper arms 10320 are curvedand spaced apart from each other to accommodate a plurality of sizes forthe cushion assembly 3002 that is releasably attachable to the frame3310. For example, the first curved section 10307 of the upper arms10320 may be spaced apart from another a predetermined distance toaccommodate a wide range of sizes for the cushion assembly 3002.

The shape of the curve of the upper arm 10320 is intended to closelyfollow the patient's cheek. The relative position of the upper arm 10320in contact with the patient's cheek during use is such that it does notslip on the patient's face. For example, the upper arm 10320 may sitslightly below the patient's cheekbone which prevents the upper arm10320 from sliding upwards. Also, contact between most of or all theinner side surface of the upper arm 10320 and the patient's face mayincrease friction to prevent slippage and ultimately minimise disruptionof sealing forces. The shape of the curved profile of the upper arm10320 directs the positioning and stabilising structure 3300 between theeyes and ears over the majority of the anthropometric range. Thisorientation is advantageous because it is aesthetic and unobtrusive fromthe perspective of the patient 1000 and the patient's bed partner 1100.

The Flexibility of Arms for the Frame 3310

The upper arm 10320 is more flexible in certain directions at certainlocations along the upper arm 10320 relative to the arm 10320 and/orframe 3310. By having a more flexible upper arm 10320 when displaced incertain directions provides the patient 1000 with greater comfort, lesslikelihood of seal disruption caused by tube torque and therefore leadsto increased patient compliance with therapy in terms of frequency ofuse and therapy duration. In an example, the upper arms 10320 are moreflexible than the lower arms 10330. Neither arm 10320, 10330 is intendedto stretch when the headgears straps 10230, 10220 are tightened.

Relative flexibility of the upper arm 10320 in different directions isalso an important consideration. For example, the upper arms 10320 maybe more flexible in the sagittal plane as shown in FIG. 60 (e.g.,laterally out direction) than other planes to accommodate variouspatient face widths. If flexibility in the transverse plane as shown inFIG. 60 (e.g., vertical down direction) is too high (i.e. equal to thelaterally out direction), there may be seal instability. In one example,the upper arm 10320 is more flexible in the laterally out direction thanthe vertical down direction. The upper arm 10320 is 9 to 10 times moreflexible in the laterally out direction than the vertical downdirection. Preferably, the upper arm 10320 is about 9.23 times moreflexible in the laterally out direction than the vertical downdirection. Tube torque may also be addressed in conjunction with othermask components such has the short tube 4180 (e.g. making it lighterweight, more slinky or more flexible) or the use of a swivel connector,ball and socket joint or gusset or pleated section. However, variedfacial widths are predominantly addressed by the flexibility of theupper arm 10320 and therefore the upper arm 10320 needs to be moreflexible in the laterally out direction compared to the vertical downdirection.

A central region 10313 of the lower arms 10330 is narrower than thedistal ends of the lower arms 10330 (see FIG. 60). This narrower centralregion 10313 provides some flexibility for the lower arms 10330 forflexing in the sagittal plane. The lower arms 10330 are substantiallyinflexible or not as flexible in the coronal and traverse planescompared to its flexibility in the sagittal plane. Controlling theflexibility of the lower arms 10330 enables the mask 3000 to be morestable and comfortable for the patient 1000. The headgear straps 10230,10220 are tightened by adjusting their length using the adjustable hookand loop connection mechanism 950. The adjustment of the length of thelower headgear straps 10220 may cause the lower arms 10330 to slightlyflex towards the patient 1000 as the mechanical retention member 10215of the headgear clip 10210 is engaged and pulls against the lowerheadgear connection point 10331 of the lower arm 10330.

Some rigidised headgear components of prior masks are more rigid thanthe frame. Typically, these stiff headgear components use threaded armsand bolts to manually adjust the headgear to fit the patient's head.Although a flexible frame may improve mask comfort, provide a good seal,minimise inadvertent leak and minimise the risk that headgear straps aretoo tight for low pressure level for therapy, some difficulty wouldarise if the flexible frame was needed to be releasably detachable witha seal-forming structure. Seal-forming structures are resilientlyflexible so that they form a seal against the patient's airways. If boththe seal-forming structure and frame are of similar flexibility (i.e.,very flexible or floppy), it would be difficult for a patient 1000 toengage these two parts together, especially a patient 1000 witharthritic hands in a darkened room.

Some rigidised headgear components of prior masks are detachable fromthe frame. Typically this is by way of a snap-fit or clip connectionbetween the rigidiser arm and the mask frame, both of which are rigidand stiff components. This type of hard-to-hard connection between therigidiser arm and frame may result in less flexibility at the point ofconnection which means more force is required to flex at this pointcausing discomfort for patients with larger face widths since a pinchingforce may be experienced when the rigidiser arms are forced to flexoutwardly. Some of these rigidiser headgear components have the hardclip at the distal end of the rigidiser arm for releasable connectionwith the frame. The hard clip is permanently connected to a headgearstrap which may damage a washing machine tub or other laundry items whenthe headgear is washed in a washing machine. Also, some of theserigidised headgear components tend to require a patient interface with awider frame which means that the headgear straps commence from the frameposition at a larger distance apart from other. The wider frame may haveintegrally formed lateral arms which are considered part of the frame asthey are made from the same material. A wider frame may be perceived bypatients 1000 and their bed partners 1110 as more obtrusive andaesthetically undesirable because they cover a larger footprint on theface. In contrast, in one example of the present technology, the upperarm 10320 is made from a material that is less flexible than theheadgear straps 3301. In other words, the headgear straps 3301 are themost flexible component of the positioning and stabilising structure3300 as it is made predominantly from a textile fabric. The second andthird most flexible component of the positioning and stabilisingstructure 3300 is the upper arm 10320 and then the lower arm 10330,respectively, in one example. The most rigid or stiff component is theframe 3310, in particular, the area of the frame 3310 proximal to theconnection port 3600, which not intended to flex, stretch or bend easilyor at all because it is the seal-forming structure 3100 that is meant toform a seal with the patient's airways by resilient deformation. Thedifferences in flexibility of individual components can control theamount of flexing at certain locations and also determine the order thatcertain components start to flex when a certain force is applied i.e.tube torque or accommodating a larger face width. The differences inflexibility of individual components may also decouple forces beforethey can begin to disrupt the seal of the seal-forming structure 3100 ina specific manner or sequence. These factors aim to address therequirements of comfort, stability and provision of a good seal at thesame time for a patient interface 3000.

Connection Between Plenum Chamber and Frame

In one form of the present technology, plenum chamber 3200 is removablyattachable to frame 3310, e.g., to facilitate cleaning, or to change fora differently sized seal-forming structure 3100. This may permit theplenum chamber 3200 to be washed and cleaned more often than the frame3310 and short tube 4180. Also, it may permit the plenum chamber 3200 tobe washed and cleaned separately from the headgear straps 3301. In analternative form, plenum chamber 3200 is not readily removable fromframe 3310.

Plenum chamber 3200 may comprise the plenum connection region 3240 (seeFIG. 81). A retaining structure 3242 of the plenum connection region3240 has a shape and/or configuration that is complementary to a shapeand/or configuration of a corresponding frame connection region 3312(see FIG. 83). The retaining structure 3242 of the plenum connectionregion 3240 is more rigid than the other parts of the plenum chamber3200, and may be made from the same material as the frame 3310, forexample, polypropylene or polyamide. In other examples, the plenumconnection region 3240 may be made from nylon, and the frame 3310 madefrom polypropylene. Nylon, polyamide and polypropylene are not floppymaterials and do not readily conform to finger pressure. Therefore, whenthey are engaged to each other, there is an audible click and a hard tohard connection. The shape of the retaining structure 3242 is depictedin FIGS. 83 and 102-105 in the form resembling a circle, paraboliccylinder or hyperbolic cylinder. The retaining structure 3242 is notstretchable and inextensible in order to maintain its general shape asit engages and disengages from the frame 3310. The shape of theretaining structure 3242 allows a slight degree of flexing but not tothe extent that opposite sides of the retaining structure 3242 are ableto touch each other if pinched together with finger pressure. In otherwords, the opposite sides of the retaining structure 3242 can only bebrought into contact together with significant pinching force intendedby the patient 1000 which would not occur under normal therapycircumstances. The retaining structure 3242 may be glued (e.g. using anadhesive) onto the plenum chamber 3200, according to an example of thetechnology, after molding. In another example, an integral chemical bond(molecular adhesion) may be utilized between the retaining structure3242 and the plenum chamber 3200.

In an example of the technology, the retaining structure 3242 may bemolded without any undercuts such that it may be molded and then removedfrom the mold tool without flexing. The retaining structure 3242 has acontinuous peripheral edge on an anterior side that contacts the frame3310. This continuous peripheral edge is exposed so that it makescontact with the frame 3310 for engagement in a hard to hard manner.This is in contrast to a majority soft to hard connection where in someprior masks there is an anterior lip portion of the seal-formingstructure that covers and overlaps the majority of a detachable rigidretaining structure. The anterior lip portion is made from LSR and wrapsover the retaining structure to hold it together. However, in such priormasks, it is difficult and cumbersome to wrap the anterior lip portionover a detachable clip and possible for the clip to be misplaced whichwould then result in the inability of connecting the seal-formingstructure to the frame.

One purpose of the retaining structure 3242 is to align the plenumchamber 3200 when engaging with the frame 3310 because the shape of theretaining structure 3242 of the plenum chamber 3200 is retained(possibly at varied depths) in a space defined between the frameconnection region 3312 and interfering portion 3314 of the frame 3310(FIG. 97).

Another purpose of the retaining structure 3242 is to retain the plenumchamber 3200 to the frame 3310 by preventing relative lateral andvertical relative movement between these two parts. Plenum connectionregion 3240 may comprise at least one retention feature 3244, 3245, andthere may be at least one complementary frame connection region 3312,3313. Plenum connection region 3240 may comprise one or more retentionfeatures 3244, 3245 (FIG. 81). In addition to preventing relativelateral and vertical movement between the plenum chamber 3200 and theframe 3310, another purpose of the retention features 3244, 3245 is toprevent relative longitudinal movement between these two parts. Theremaining portion of plenum chamber 3200 may comprise a more flexiblematerial than the retaining structure 3242 and plenum connection region3240.

In one form, plenum connection region 3240 is constructed from a rigidor semi-rigid material, e.g. high durometer silicone or TPE, plastic,nylon, a temperature resistant material, polypropylene, and/orpolycarbonate. Plenum connection region 3240 may be constructed from adifferent material to other portions of plenum chamber 3200. For exampleplenum connection region 3240 may be a separate component that ispermanently connected, integrally bonded or mechanically interlockedwith connection portion 3202 (FIG. 81) of the plenum chamber 3200.Turning to FIG. 89, the connection portion 3202 of the plenum chamber3200 may have substantially the same thickness as the retainingstructure 3242 of the plenum connection region 3240. Plenum connectionregion 3240 may include a tongue portion 3211 constructed and arrangedto be matingly received by a channel portion 3211.1, e.g., a channelportion of a frame 3310 (FIG. 92). In this way, the channel portion3211.1 may form a mating feature for the tongue portion 3211, and viceversa. Also, the tongue portion 3211 and the channel portion 3211.1 maybe dimensioned to maximize the sealing surface area in this region.

Attachment and Removal of Plenum Chamber from Frame

The plenum chamber 3200 may be fixedly attached to the frame 3310, butit also may be removably attached to the frame 3310. FIG. 90 shows theconnection portion 3202 of the plenum chamber 3200 in a connectedposition relative to the frame 3310. Plenum connection region 3240includes in this example only the retention feature 3244, which ispositioned on the connection region 3240. FIG. 90 shows a cross-sectionthat passes through a barb 3246, while FIG. 92 shows anothercross-section where the barb 3246 is not present, forming e.g. a channelor groove 3211.1. The resilient barb 3246 is a type of snap-incompression-fit member to provide a high retention force (to preventaccidental disengagement) and also enable relatively easy intentionalremoval. In FIG. 92, the plenum connection region 3240 and the frame3310 simply fit together in a tongue and groove like manner. The frame3310 and retaining structure 3242 may be shaped so that the tongueportion 3211 and the channel portion 3211.1 engage before the retentionfeatures 3244, 3245 engage with the frame 3310. This may help align theretention features 3244, 3245 for connection.

The plenum connection region 3240 (see FIG. 81) that connects to theframe 3310 consists of two “snap features/barbs” (of different widths,e.g., the retention features 3244, 3245) located at the top and bottom.This enables an easy one-way assembly with the frame and providessufficient retention during use. When assembled to the frame 3310, asilicone lip seal 3250 around the internal perimeter of the cushionassembly 3002 is deflected against the interfering portion 3314 on theframe 3310, as shown in FIG. 90. This interference provides an air sealbetween the cushion assembly 3002 and the frame assembly 3001 which ispositively reinforced under pressure. Disassembly of the cushionassembly 3002 from the frame assembly 3001 is assisted by pinching thecushion assembly 3002 at the two “snap feature” locations (e.g., theretention features 3244, 3245) at top and bottom portions and pullingaway from the frame 3310. In an example, the retaining structure 3242may be structured for repeatable engagement with and disengagement fromthe frame.

Each retention feature 3244, 3245 may take the form of a barb 3246(FIGS. 89 and 90) having a leading surface 3246.1 and a trailing surface3246.2. The leading surface 3246.1 is adapted to engage a lead-insurface 3312.1 of the frame connection region 3312 of the frame 3310, asthe plenum chamber 3200 and the frame 3310 are moved into engagementwith one another. As the retention feature 3244 is pushed into positionit deforms, as shown in FIGS. 95 and 96. Also, upper and lower regionsof the frame connection region 3312 and interfering portion 3314 of theframe 3310 may also slightly deform. Also, the retaining structure 3242may also slightly deform especially near the retention feature 3244 (forexample, see broken line in FIGS. 95 and 96). Turning to FIGS. 98 to102, deformation of the frame connection region 3312 and interferingportion 3314 of the frame 3310 is controlled in terms of the amount ofdeformation permitted and also the areas of where deformation is tooccur through the use of ribs 3294. In one example of the presenttechnology, there are four ribs 3294 spaced around and against theinterfering portion 3314, however more than four or less than four ribsare possible. The spacing and position of the ribs 3294 limit the areaof deformation of the interfering portion 3314 to only the area proximalto the retention features 3244, 3245. The ribs 3294 may also abut anddeform against the inner surface of the plenum connection region 3240 toprovide a firmer engagement between the plenum connection region 3240and the frame connection region 3312 at these contact points when theplenum chamber 3200 is engaged with the frame 3310. Turning to FIGS. 102to 105 which shows the plenum connection region 3240 independent fromthe plenum chamber 3200, the plenum connection region 3240 of the plenumchamber 3200 may have notches 3295 to correspond with the ribs 3294. Thenotches 3295 may be chamfers to minimise the friction of the plenumconnection region 3240 against the ribs 3294 during assembly of theplenum chamber 3200 with the frame 3310. Once the barb 3246 is pushed ina sufficient amount, it snaps outwards in a radial sense such that thebarb 3246 assumes a retained position shown in FIG. 90. The snappingaction results in an audible sound to the user such as a re-assuringclick sound, providing feedback to the user or patient that a properconnection has been established. In the retained position, the trailingsurface 3246.2 of the barb 3246 engages with a retaining surface 3312.2of the frame connection region 3312, as shown in FIG. 90. Thisreassuring click sound may also be facilitated, in one example of thetechnology, by forming the plenum connection region 3240 of sufficientstiffness, that stiffness being greatest near the plenum connectionregion 3240. This stiffness may be accomplished by overmoldingmanufacturing.

To promote ease of use, over-molding technology is used in the nasalmask design to reduce the number of user/patient identifiablesubassemblies. The components that make up the frame 3310 and tubesubassembly 4180 are over-molded into one fully integrated frameassembly 3001. These components include the frame 3310, two magnets10340 on the lower arms 10330 and the short tube 4180. The swiveladapter and a rotating swivel 4190 are later attached to the distal endof the short tube 4180. Once assembled, this integrated frame 3310 andshort tube assembly 4180 from the arms 10320, 10330 to the rotatingswivel end 4190 is designed to be handled, cleaned and disinfectedwithout the need for disassembly. The frame 3310 acts as the chassis forthe cushion assembly 3002, which connects via snap features orconnection regions 3312, 3313 and it also provides the sealing surfaceto achieve a cushion 3100 to frame 3310 air seal.

The swivel assembly 4190 itself consists of two parts permanentlyassembled into one unit. The swivel adapter 4190 interfaces between theshort tube 4180 and the swivel. The swivel component can rotate a full360° between the swivel adapter 4190 and the PAP system air deliveryhose 4178.

As can be seen in FIG. 90, the surfaces of the barb 3246 and the frameconnection region 3312 are angled in certain manners to facilitatesliding connection between the plenum chamber 3200 and the frame 3310.For example, as stated above, the leading surface 3246.1 and the lead-insurface 3312.1 may be formed with angles corresponding to one anothersuch that these to surfaces may slidingly engage with one another withrelative ease. Similarly, the trailing surface 3246.2 and the retainingsurface 3312.2 may be angled relative to one another to help retain theframe 3310 and the plenum chamber 3200 once connected. The anglesbetween the trailing surface 3246.2 and the retaining surface 3312.2 areselected such that a pulling force applied, e.g., generally along theaxis of the seal-forming structure 3100, is sufficient to cause the barb3246 to flex inwardly to thereby release the plenum chamber 3200 fromthe frame 3310. This pulling force does not require the patient 1000 tofirst deflect the barbs 3246 radially inwards, e.g., by squeezing theplenum chamber 3200 in an anterior-posterior direction. Rather, due tothe angles involved, the radial deflection of the barbs 3246 occurssolely as a result of the axial pulling force applied. In one example ofthe present technology, the plenum connection region 3240 is deflectedand disassembly of the plenum chamber 3200 from the frame 3310 isperformed by pinching the plenum chamber 3200 (e.g., squeezing theplenum chamber 3200 on its lateral sizes (left and right)) and pullingthe plenum chamber 3200 away from the frame 3310.

As can be seen in FIG. 90, the plenum chamber 3200 is attached to theframe 3310 via the plenum connection region 3240 and the retentionfeature 3244 is engaged with the frame connection region 3312 by thebarb 3246. Also shown in this view, the retaining surface 3312.2 of theframe connection region 3312 and the trailing surface 3246.2 of the barb3246 are engaged and flush with one another. For the patient to detachthe plenum chamber 3200 from the frame 3310 the patient 1000 must pullthe plenum chamber 3200 with respect to the frame 3310 with sufficientforce to overcome the resistance of the retaining surface 3312.2 againstthe trailing surface 3246.2. In one example of the present technology,pinching the plenum chamber 3200 reduces the axial pulling forcerequired to detach the plenum chamber 3200 from the frame 3310. Thisresistance can be “tuned” or selectively adjusted to a desired level byvarying the angle at which these surfaces 3312.2, 3246.2 engage with oneanother. The closer to perpendicular these surfaces 3312.2, 3246.2 arewith respect to the direction of the force applied by the patient 1000to detach the plenum chamber 3200 from the frame 3310, the greater theforce required to cause the detachment. This angle is shown as β in FIG.91, where the trailing surface 3246.2 is angled with respect to anominal vertical axis 3246.4 (corresponding to axial pull direction ofplenum chamber 3200 to the frame 3310). As β is increased, the forcerequired to detach the plenum chamber 3200 from the frame 3310 rises.Furthermore, as β increases the detachment will feel more abrupt to thepatient 1000. In one example, an angle β of approximately 75 degrees hasbeen found to generate a comfortable feel of detachment for the patient.In further examples, β may vary from 30 to 110 degrees or from 40 to 90degrees or from 65 to 85 degrees to generate an ideal level ofresistance to detachment. This has been selected to minimise thelikelihood of accidental detachment, and to only permit intentionaldetachment by the patient 1000.

Angle α, the angle between the nominal vertical axis 3246.4 and theleading surface 3246.1, can likewise be “tuned” or selectively adjustedto require a specific level of force when the patient 1000 attaches theplenum chamber 3200 to the frame 3310. As angle α is increased, theforce required to engage the retention feature 3244 with the frameconnection region 3312 increases and the feeling of attachment for thepatient engaging these components 3244, 3312 becomes more abrupt. Inother words, as the leading surface 3246.1 of the retention feature 3244slides along the lead-in surface 3312.1 of the frame connection region3312 the patient 1000 may experience a smoother feel of engagement asangle α decreases. In one example, an angle α of approximately 30degrees has been found to generate a comfortable feel of attachment forthe patient 1000. In further examples, angle α may vary from 50 to 70degrees or from 15 to 60 degrees to generate an ideal level ofresistance to attachment.

Furthermore, since the feel and force of engagement and disengagement ofthe plenum chamber 3200 and frame connection region 3312 can be tuned orselectively adjusted independently of one another, angles α and β may bechosen to cause the patient to feel a level of resistance to attachmentthat is different from the level of resistance of detachment. In oneexample of the technology, angles α and β may be chosen such that angleβ is greater than angle α, such that the patient feels less resistanceto attachment of the plenum chamber 3200 and frame 3310 than resistanceto detachment. In other words, it may feel harder for the patient 1000to disconnect the plenum chamber 3200 from the frame 3310 than toconnect them.

As can be seen in FIG. 82, one example of the technology includes a pairof retention features 3244, 3245. Also shown in this view, the exemplaryretention features 3244, 3245 are differently sized. Particularly, thisview shows that the narrow retention feature 3245 disposed on aninferior portion of the plenum connection region 3240 is narrower thanthe wide retention feature 3244 disposed on the superior portion of theplenum connection region 3240. By sizing the retention features 3244,3245 differently, the patient 1000 is only able to attach the plenumchamber 3200 to the frame 3310 in one orientation and preventmisalignment. Such an arrangement is shown in FIG. 82. This avoidspatient frustration during attachment, minimises damage to the patientinterface 3000 that may arise from incorrect attachment, ensures theseal-forming structure 3100 is in the correct orientation to provide aproper seal against the patient's airways and provide comfort byreducing or avoiding concentration of contact force, in particular atthe upper lip of the patient 1000.

In FIG. 88, frame connection region 3312 is shown in engagement withcorresponding retention feature 3244. The wider retention feature 3312is engaged with the correspondingly sized frame connection region 3244.In the example depicted here, the narrow retention feature 3245 is sizedto correspond to the narrow anterior frame connection region 3313,although their engagement is not visible. An arrangement such as this,where one retention feature is uniquely dimensioned to engage with acorresponding uniquely dimensioned frame connection region, has theadvantage that the patient will only be able to attach the plenumchamber 3240 to the frame 3310 in one orientation. By limiting theorientations of attachment, the patient 1000 is prevented fromassembling the patient interface 3000 improperly and receivingsuboptimal therapy due to an improperly assembled patient interface3000. The arrangement described with respect to this particular exampleof the technology is advantageous to the patient 1000 that may havedifficulty seeing how to correctly engage the components due to visionproblems or the patient 1000 who may be assembling the patient interface3000 in a dark room, e.g., the bedroom before sleep, because the patient1000 will only be able to completely assemble the patient interface 3000if the components are properly aligned.

As described above, the angles of the leading surface 3246.1 and thetrailing surface 3246.2 on the barb 3246 are important to providing anoptimum amount of resistance to assembly and disassembly of the patientinterface 3000. Also described above is the benefit of sizing respectiveretention features 3244, 3245 and frame connection regions 3312, 3313correspondingly such that a proper orientation of the components isensured upon assembly. Properly dimensioning the retention features3244, 3245 and the frame connection regions 3312, 3313 may help to guidethe plenum chamber 3200 onto the frame 3310. In other words, the frameconnection regions 3312, 3313 and the retention features 3244, 3245 maybe dimensioned in close conformity to one another such that theperimeter of the frame connection regions 3312, 3313 and the perimeterof the retention features 3244, 3245 aid in directing and aligning theretention feature 3244, 3245 into respective frame connection regions3312, 3313. This may be beneficial to a patient with limited dexteritydue to a disease (e.g., arthritis) or a patient assembling the patientinterface 3000 where visibility is diminished whether in a dark bedroomprior to sleep or due to limited vision. Also, by dimensioning theretention features 3244, 3245 and the frame connection regions 3312,3313 in close conformity to one another this serve to ensure that theseal between the plenum chamber 3200 and the frame 3310 is maintained byfacilitating a secure connection between these two components.Additionally, close conformity between the retention features 3244, 3245and the frame connection regions 3312, 3313 may serve to facilitateequal alignment of the plenum chamber 3200 on the frame 3310. In oneexample of the present technology a difference of 0.3 mm to 2 mm may beincorporated between the retention features 3244, 3245 and the frameconnection regions 3312, 3313.

It should also be understood that connection between the frame 3310 andthe plenum chamber 3200 described above and below may be used with othertypes of masks. Such features may be applicable to full-face masks aswell. Masks that seal under the bridge of the nose, such as compactnasal masks or compact full-face masks, may also incorporate theconnection features described herein. Furthermore, masks that lack aforehead support may also include these connection features. It is alsoenvisioned that examples of the present technology that include masksthat seal below the tip of the nose, such as a nasal cradle/nasal flange3101, may also use these connection features.

Plenum Chamber and Frame Attachment and Removal Sequence

FIGS. 93 to 97 show a sequence of cross-sectional views of theconnection portion 3202 of the plenum chamber 3200 and the frameconnection region 3312 of the frame 3310. These sequential views showthe process of attachment of the plenum chamber 3200 to the frame 3310.While these views show only the attachment of one retention feature 3244to one frame connection region 3312, it should be understood that theremay be more than one retention feature 3244 and more than one frameconnection region 3312, as can be seen in FIGS. 53 to 55, 69, and 81 anddiscussed above. Therefore, during the attachment sequence of the plenumchamber 3200 and the frame 3310 there may be more than one instance ofthe depicted attachment sequence taking place to accomplish completeattachment of the plenum chamber 3200 and the frame 3310.

FIG. 93 shows a cross-sectional view of the connection portion 3202 ofthe plenum chamber 3200 and the frame connection region 3312 of theframe 3310 where the connection portion 3202 and the frame connectionregion 3312 are near one another but not in contact. The arrow indicatesthat the connection portion 3202 and the frame connection region 3312are being brought together. It should be understood that for these viewsadditional portions of the plenum chamber 3200 and the frame 3310 havenot been included in the interest of simplicity. Thus, it should also beunderstood that frame connection region 3312 and interfering portion3314 of the frame connection region 3312 are both part of the frame 3310as can be seen, for example, in FIG. 90. Moreover, it should beunderstood then that the frame connection portion 3312 and theinterfering portion 3314 of the frame connection portion 3312 will moverelative to one another through the attachment sequence. Returning toFIG. 93, this view shows that the sealing lip 3250 is not deformed andthe retention feature 3244 is not deformed as neither of thesecomponents 3250, 3244 are in contact with the frame 3310.

FIG. 94 shows the barb 3246 of the retention feature 3244 beginning tomake contact with the frame connection region 3312 of the frame 3310.Specifically, this view shows the leading surface 3246.1 of the barb3246 in contact with the lead-in surface 3312.1 of the frame connectionregion 3312. In this view, the retention feature 3244 and the frameconnection region 3312 are only just coming into contact with oneanother such that the retention feature 3244 is not deflected. Also, thesealing lip 3250 has not been deflected because it is not yet in contactwith the interfering portion 3314 of the frame connection region 3312.As described above, the angle α of the leading surface 3246.1 will beginto affect the resistance the patient 1000 will feel to engagement of theplenum chamber 3200 and the frame connection region 3312 because theleading surface 3246.1 will begin to engage in frictional contact withthe lead-in surface 3312.1.

FIG. 95 shows the plenum chamber 3200 and the frame 3310 further alongin the attachment sequence such that the retention feature 3244 isdeflected by contact with the frame connection region 3312. As can beseen in this view, the frame connection region 3312 and the interferingportion 3314 of the frame connection region 3312 are nearer to theconnection portion 3202. Also shown in this view, the leading surface3246.1 of the barb 3246 is in contact with a portion of the lead-insurface 3312.1 that is closer to the retaining surface 3312.2. In otherwords, the barb 3246 can be seen having moved closer to attachment withthe frame connection region 3312 and having moved relative to theposition shown in FIG. 94. As described earlier, the connection portion3202 and the plenum connection region 3240 of the plenum chamber 3200may also be deflected from a pinching force generated by the patient1000. FIG. 95 also indicates that the retention feature 3244 has beendeflected by contact with the frame connection region 3312 and thedashed lines show the outline of the retention feature 3244 in anundeformed state. FIG. 95 also shows that the sealing lip 3250 is notyet in contact with the interfering portion 3314 of the frame connectionregion 3312, and, therefore, the sealing lip 3250 is not deformed.Although, not shown in this view it should also be understood that theframe connection region 3312 may deflect away from the retention feature3244 due to the force of these parts 3312, 3244 being forced together.

In FIG. 96 the plenum chamber 3200 and the frame 3310 are nearlyattached and the retention feature 3244 is nearly completely engagedwith the frame connection region 3312. In this view the retentionfeature 3244 is still deformed but the barb 3246 is in contact with adifferent portion of the frame connection region 3312. Specifically, thetrailing surface 3246.2 of the barb 3246 is now in contact with theretaining surface 3312.2 of the frame connection region 3312. Also, dueto the fact that the angle at which the trailing surface 3246.2 and theretaining surface 3312.2 contact one another, the retention feature 3244and the frame connection region 3312 may be urged into engagement by theinherent tendency of the deflected retention feature 3244 to return toits undeformed state, in effect drawing these parts together after acertain insertion distance is reached. FIG. 96 also shows the outline ofthe retention feature 3244 in an undeformed state with dashed lines.Also in this view it can be seen that the sealing lip 3250 is in contactwith the interfering portion 3314 of the frame connection region 3312.At this point in the attachment sequence a seal may begin to be formedby the contact of the sealing lip 3250 and the interfering portion 3314of the frame connection region 3312. The sealing lip 3250 may also beslightly deflected by contact against the interfering portion 3314 ofthe frame connection region 3312.

FIG. 97 shows the plenum chamber 3200 and the frame 3310 fully attachedby engagement of the barb 3246 of the retention feature 3244 with theframe connection region 3312. In this view the retaining surface 3312.2may be relatively flush against the trailing surface 3246.2. Theretention feature 3244 may also no longer be deflected by contact withthe frame connection region 3312. The retention feature's 3244 return toan undeformed state from its deflected or deformed state, as shown inFIG. 96, may generate an audible click as the barb 3246 and theretention feature 3244 move to the position shown in FIG. 97 from theposition shown in FIG. 98. This re-assuring audible click may beadvantageous in that it provides the patient 1000 with feedback that theplenum chamber 3200 and the frame 3310 are fully engaged. By providingthe patient 1000 with this feedback upon completion of engagement thepatient 1000 may be able to use the patient interface 3000 withconfidence that the plenum chamber 3200 and the frame 3310 are securelyattached and will not separate while the patient 1000 is asleep andreceiving therapy.

Furthermore, a desired level of sealing contact may be achieved when theplenum chamber 3200 and the frame 3310 are attached as shown in FIG. 97.The sealing lip 3250 can be seen deflected against the interferingportion 3314 of the frame connection region 3312. By being deflected asshown, the sealing lip 3250 may be urging itself against the interferingportion 3314 of the frame connection region 3312 with sufficient forcedue to the tendency of the sealing lip 3250 to return to its undeformedstate such that a desired seal is generated between these components.Furthermore, as air pressure within the plenum chamber 3200 increaseswhen therapy is applied, the sealing lip 3250 is forced to deflecttowards the portion 3314 of the frame connection region 3312 therebyincreasing the sealing force in this area. Even though a compressionseal is formed between the retaining structure 3242 and frame connectionregion 3312 when the plenum chamber 3200 is engaged with the frame 3310,a pressure-activated seal also is formed between sealing lip 3250 andthe portion 3314 of the frame connection region 3312 on engagement whichstrengthens as air pressure within increases. It may be possible incertain examples that the compression seal is not air tight resulting inundesired leakage.

Also, if a very large amount of compression of components is required toform the compression seal, this may hinder easy attachment anddetachment of the plenum chamber 3200 to the frame 3310 possiblyrequiring more than a single hand to perform the operation or asignificant amount of effort. Therefore, in one example of the presenttechnology, the compression seal functions predominantly for the purposeof retention rather than of seal, and the pressure-activated sealfunctions predominantly for the purpose of creating and maintaining anair tight seal. It should be understood that such a sealing effect maybe occurring about the periphery of the junction between the plenumchamber 3200 and the frame 3310. For example, FIG. 92 shows the sealinglip 3250 in a similarly deflected state against the frame connectionregion 3312 at a region separate from the retention features 3244.Moreover, it can be seen in FIGS. 80 and 81, for example, that thesealing lip 3250 extends around the perimeter of the plenum chamber3200. By extending the sealing lip 3250 inwardly around the perimeter ofthe junction between the plenum chamber 3200 and the frame 3310 thedesired level of sealing can be achieved throughout this region, therebypreventing undesired leakage of pressurized gas.

Additionally, it should be understood that the sealing lip 3250 may bepressing against the interfering portion 3314 of the frame connection3312 with a force that is urging these parts to separate. However, thefriction force due to structural engagement of the trailing surface3246.2 of the barb 3246 with the retaining surface 3312.2 of the frameconnection region 3312 should be sufficient to resist the force of thesealing lip's 3250 tendency to return to an undeformed state andseparate the plenum chamber 3200 from the frame 3310.

As for removal of the plenum chamber 3200 and the frame 3310, it shouldbe understood that this process is substantially the reverse order ofthe process described above. In other words, the patient 1000 mayseparate the plenum chamber 3200 from the frame 3310 by pulling thesecomponents in opposite directions and the view of FIG. 97 may be thebeginning of the separation process and FIG. 25 may represent the viewwherein the plenum chamber 3200 and the frame 3310 are fully separated.Pinching of the plenum chamber 3200 proximal to the plenum connectionregion 3240 or pinching the plenum connection region 3240 and pullingaway from the frame 3310 may assist in removal of the plenum chamber3200 from the frame 3310. It is also envisaged that the patient 1000 maypinch the plenum chamber 3200 for the purpose of gripping it, at anylocation and simply pull it away from the frame 3310. A twisting motionwhile pulling may also assist in disengaging the plenum chamber 3200from the frame 3310.

Hard-to-Hard Connection

The plenum connection region 3240 and the frame 3310 may be assembledand attached as shown in FIGS. 93 to 97. As stated above, the plenumconnection region 3240 and/or retaining structure 3242 may be comprisedof a semi-rigid material, e.g., high durometer silicone (a higherdurometer than plenum chamber 3200)/TPE, plastic, nylon, polypropylene,polyamide and/or polycarbonate. The plenum connection region 3240 can beconstructed in the form of a continuous ring or oval, two C-shapedclips, one C-shaped clip, or a single continuous piece but onlysurrounding a part of the plenum chamber 3200. The clip may function asa spring clip and be in the form of a C-section or double C-section. Thespring force of the spring clip may be provided by resiliency of theplenum connection region 3240 being stretched against the frameconnection regions 3312, 3313 or interfering portion 3314 of the frame3310. In another example, a clip form may be not be necessary and onlythe retention features 3244, 3245 are permanently and directly connectedto the plenum chamber 3200 without a plenum connection region 3240and/or retaining structure 3242 for engagement with the connectionregions 3312, 3313. It is also envisioned that one example of thepresent technology may also include the frame 3310 being comprised ofthe same or a similar semi-rigid material as the plenum connectionregion 3240. By manufacturing the frame 3310 and the plenum connectionregion 3240 of semi-rigid material, a “hard-to-hard” connection orbonding interface may be created, e.g., releasable hard-to-hardconnection. This “hard-to-hard” connection, in conjunction with thestructural features of the plenum connection region 3240 and the frameconnection region 3312, may provide the patient 1000 with a confidentfeeling (e.g., by providing an audible snap fit or re-assuring clicksound) of the connection between the plenum chamber 3200 and the frame3310 when assembling the patient interface 3000. Since a secure fitbetween the plenum chamber 3200 and the frame 3310 is helpful to ensurethat the patient 1000 receives optimal therapy through the patientinterface 3000, a design that provides the patient 1000 with ease of useand confidence that a secure fit has been achieved is beneficial. Ahard-to-hard connection as described herein may also be beneficial inthat it may add stability to the seal made by the seal-forming structure3100. This is contrast to a hard-to-soft or a soft-to-soft connectionwhere either or both the plenum chamber and frame are made of a floppymaterial which makes it difficult for arthritic hands to properly engagethe plenum chamber and frame easily, especially in darkened room. The“hard-to-hard” connection also provides a simple attachment andreattachment of the seal-forming structure 3100 to the frame 3310.

Although the retention features 3244, 3245 are described as provided onthe plenum chamber 3200 and the connection regions 3312, 3313 areprovided on the frame 3310, it may be possible to switch the location tothe retention features on the frame and the connection regions on theplenum chamber. Also, there may be a combination of a retention featureand a connection region on one part that corresponds with a connectionregion and a retention feature on the other part.

Method of Making the Plenum Chamber

A process to manufacture plenum chamber 3200 may comprise the step ofmolding plenum connection region 3240 in a first tool, removing moldedplenum connection region 3240 from the first tool, inserting the plenumconnection region 3240 into a second tool, and molding a portion ofplenum chamber 3200 comprising connection portion 3202 in the secondtool. Plenum connection region 3240 may be chemically bonded and/ormechanically interlocked to connection portion 3202.

In one form, the sealing lip 3250 is constructed and arranged tointerfere with the interfering portion 3314 (FIG. 90) of frameconnection region 3312 when plenum chamber 3200 and frame 3310 areassembled together. In use, sealing lip 3250 is caused to resilientlyflex away from a resting position (FIG. 89) when assembled with theinterfering portion 3314 of frame connection region 3213, and at leastin part as a result of being a resilient material, pushes against theinterfering portion 3314 (FIG. 90) to resist or prevent leakage of airbetween sealing lip 3250 and the interfering portion 3314. Although thesealing lip 3250 has been described as provided with the plenum chamber3200, the sealing lip 3250 may be provided on the frame 3310. Althoughone sealing lip has been described, it is possible two or more sealinglips may be provided, with at least one with the plenum chamber 3200 andat least one with the frame 3310.

Positioning and Stabilising Structure 3300

Note that in one form of the present technology, a number of structuralfeatures form part of a positioning and stabilising structure 3300,e.g., a headgear assembly (which may be referred to simply as headgear).In an alternative form of the present technology, one or more of thosefeatures are located on the frame 3310.

The seal-forming structure 3100 of the patient interface 3000 of thepresent technology may be held in sealing position in use by thepositioning and stabilising structure 3300 (FIGS. 75, 76 and 166). Inone form, the positioning and stabilising structure 3300 comprisesheadgear. It should be appreciated that the positioning and stabilisingstructure 3300 may, in one form of the technology, be referred to asheadgear.

Headgear straps 3301 may be removably connectable to a portion of thepatient interface 3000 such as the positioning and stabilising structure3300 via upper and lower arms 10320, 10330 of the frame 3310.

The positioning and stabilising structure 3300 may comprise two pairs ofside straps: a pair of upper side straps 10230 and a pair of lower sidestraps 10220, connected to a neck strap 10227 or circular crown strap10225. The upper side straps 10230 connect to the upper headgearconnection points 10325 to define a main headgear loop that may bepositioned along the sides of the patient's face extending substantiallyfrom between the eyes and the ears of the patient 1000, to the crownstrap 10225. The side straps 10230, 10220 include an adjustable hook andloop (Velcro™) connection mechanism 950 to connect to the headgearconnection points 10325, 10331 on the Y shaped headgear connector 800 orthe frame 3310.

The connection points 10325, 10331 comprising both a retention mechanismto retain the connection of the headgear straps 3301 to the connectorand a separate adjustment mechanism to adjust the headgear strap tensionfor sealing. The separation of the retention mechanism and theadjustment mechanism allows for the headgear straps 3301 to be adjustedindependently of connecting the headgear straps 3301 to the connector.The independent adjustment allows for a ‘set and forget feature’, whichallows for the headgear straps 3301 to be adjusted or ‘set’ then left inthis adjusted position when wearing or removing the headgear straps 3301thereby allowing the patient 1000 to ‘forget’ their previous setting.

Positioning and stabilising structure 3300 may comprise two pairs ofside straps, a pair of upper headgear straps 10230 and a pair of bottomheadgear straps 10220, connected to a neck strap 10227 or circular crownstrap 10225. The upper headgear straps 10230 connect to the upperheadgear connection points 10325 to define a main headgear loop that maybe positioned along the sides of the patient's face extendingsubstantially from between the eyes and the ears of the patient, to thecrown strap 10225. The upper headgear straps 10230 comprise anadjustable Velcro™-like connection mechanism 950 to connect to upperheadgear connection points 10325 on the upper arms 10320 of the frame3310.

An exemplary positioning and stabilising structure 3300 is disclosed inPCT publication WO 2010/0135785, filed 28 May 2010, which isincorporated herein by reference in its entirety.

In an example, the seal-forming structure 3100 of the patient interface3000 of the present technology is held in sealing position in use by thepositioning and stabilising structure 3300.

In another form of the present technology, the seal-forming structure3100 of the patient interface 3000 of the present technology is held insealing position via a four-point connection to a positioning andstabilising structure 3300.

The positioning and stabilising structure 3300 holds the cushionassembly 3002 onto the face of the patient 1000. The headgear straps3301 are shaped to conform to the head of the patient 1000. The headgearstraps 3301 may be made from a premium rolled edge fabric that reducesfacial marking, and is comfortable and easy to fit. The headgear straps3301 consist of a circular crown construction that encapsulates thecrown of the head. Two pairs of horizontally oriented upper headgearstraps 10230 extend from the top crown strap 10225 to the front of thepatient's face and these are secured to the frame 3310. The ends of thetwo upper headgear straps 10230 are threaded through the upper arms10320, folded back and then fastened using adjustment or fasteningmembers, for example, Velcro™-like hook tabs 950. These upper headgearstraps 10230 facilitate an air seal around the patient's nose bridgearea. The lower headgear straps 10220 are similarly threaded through andsecured to the two over-molded magnetic headgear clips 10210 using thesame type of Velcro™-like hook tabs 950. The headgear clips 10210self-locate and engage with the two corresponding halves located on thelower arms 10330 of the frame 3310. These two lower headgear straps10220 hold the silicone seal-forming structure 3100 against thepatient's face and they enable the bottom and sides of the seal-formingstructure 3100 to achieve air seal with the patient's face.

Length of the headgear straps 3301 are easily adjusted by unfasteningthe Velcro™-like hook tabs 950 and sliding the straps 10220, 10230through either the upper arms 10320 or the headgear clips 10210 andrefastening the hook tabs 950. Once the hook tabs 950 are fastened andset, the headgear can be quickly and easily removed by disengaging oneof the headgear clips 10210. The fastened Velcro™-like hook tab 950helps to maintain the headgear settings for next use. The headgear ismade of a triple layered laminate (fabric, foam and fabric) cut intostraps 10220, 10230, 10225, 10226 and a neck strap 10227, ultrasonicallywelded together, as illustrated. In an example, at least some of thestraps (e.g., straps 10220, 10230, 10225, 10226) may be formed bystraight cuts and are in straight lines with straight edges, e.g., tosave cost because there is less material waste if they are cut from asheet of material.

FIGS. 115 to 121 show sequential steps for fitting a patient interface3000 to a patient in accordance with one form of the present technology.For example, the seal-forming structure 3100 is first engaged with thepatient's face and the top crown strap 10225, neck strap 10227, lateralcrown straps 10226 and lower headgear straps 10220 are passed over thetop of the patient's head as shown in FIG. 115. The top crown andlateral crown straps 10225, 10226 are engaged with the patient's head toencapsulate the crown of the head (FIG. 116), and then the headgearclips 10210 associated with the lower headgear straps 10220 are engagedwith the lower arms 10330 of the frame 3310 (FIG. 116). The length ofthe upper headgear straps 10230 and/or the lower headgear straps 10220may be manually adjusted (FIGS. 118 and 119). Finally, the air circuit4170 may be connected to the short tube 4180 provided to the patientinterface (FIG. 120), and then the patient interface may be manuallyadjusted or fine-tuned on the face for comfort and fit (FIG. 121).

As shown in FIGS. 122 and 123, the patient interface 3000 may be quicklyand easily removed from the patient's head by disengaging one of theheadgear clips 10210 (FIG. 122) and pulling the headgear up and over thepatient's head (FIG. 123).

FIGS. 124 to 126 show various steps for disassembling a patientinterface 3000 in accordance with one form of the present technology.For example, FIG. 124 shows the Velcro™-like hook tabs 950 of an upperheadgear strap 10230 unfastened and being pulled and disengaged from theupper arm 10320, FIG. 125 shows the cushion assembly 3002 being squeezedor pinched on its lateral sides to remove it from the frame 3310, andFIG. 126 shows an upper arm sleeve 10312 being slid off and removed fromthe upper arm 10320.

FIGS. 127 to 130 show various steps for reassembling a patient interface3000 in accordance with one form of the present technology. For example,FIG. 127 shows the cushion assembly 3002 being squeezed on its lateralsides and pushed into engagement with the frame 3310, FIG. 128 shows anupper arm sleeve 10312 being slid onto and assembled to the upper arm10320, FIG. 129 shows the Velcro™-like hook tabs 950 of an upperheadgear strap 10230 being threaded through the upper arm 10320, andFIG. 130 shows the Velcro™-like hook tabs 950 of a lower headgear strap10220 being threaded through the headgear clip 10210, folded back andthen fastened.

FIGS. 64 to 67, 72, 84 and 86 depicts headgear straps 3301 for thepositioning and stabilising structure 3300 according to the disclosedtechnology. A crown assembly of the headgear comprises neck strap 10227,lateral crown straps 10226 and top crown strap 10225. Neck strap 10227is connected to lateral crown straps 10226 and lower headgear straps10220. Lateral crown straps 10226 and the top crown strap 10225 areconnected in thinned connecting portions 10223 providing increasedflexibility. The thinned connecting portions 10223 may have asubstantially V-shape and are preferably at least partially spaced apartfrom each other. The thinned connecting portions 10223 may be weldedportions.

The neck strap 10227 comprises two major side edges 10228, 10229. Inthis example, major side edges 10228, 10229 have a generally curvedshape. Major side edges 10228, 10229 interconnect two minor side edges10231, 10232. Minor side edges 10231, 10232 are located remotely orlaterally of the axis of symmetry of the neck strap 10227. The minorside edges 10231, 10232 each comprise three edge portions.

The width of neck strap 10227 is reduced in the concave curved part ofopposing major side edges 10228, 10229, measured in a directionperpendicular to an axis perpendicular to the axis of symmetry of theneck strap 10227. Lateral crown straps 10226 are connected orconnectable to neck strap 10227 in respective upper connecting portions10222. Lower headgear straps 10220 are connected or connectable to neckstrap 10227 in respective lower connection portions 10221. Lowerconnection portions 10221 of the depicted example extend generallyperpendicular to the main axis of the respective lower headgear straps10220. Here, upper connection portions 10222 are oriented in an acuteangle to the main axis of extension of the respective lateral crownstraps 10226.

Each strap 10230, 10220 which connects to the frame 3310 is providedwith a hook and loop tabs 950. By welding the top crown strap 10225 tothe lateral crown straps 10226 which are welded to the lower headgearstraps 10220, the final three-dimensional crown assembly is obtained.

Magnetic Headgear Engagement

One form of engagement between the positioning and stabilising structure3300 and the frame 3310 may be via magnetic engagement. This providesconvenience for the patient 1000 because it functions as a “set andforget” memory avoiding the patient 1000 having to adjust the lengths ofheadgear straps 3301 and using the hook and loop tabs 950 every timethey don and doff the patient interface 3000. Magnetic engagement alsoprovides ease of use and aids patients 1000 with arthritic hands in lowlight conditions because the magnetic attraction intuitively brings orguides the headgear clip 10210 towards the lower headgear connectionpoint 10331 on the lower arm 10330 when they are in proximity with eachother. This provides self-alignment and an audible click on successfulengagement enables fast fitting for patients 1000 allowing them to startor resume therapy quicker.

The lower arms 10330 may comprise magnets 10340 enclosed or embedded ina distal free end of the lower arms 10330 at the lower headgearconnection points 10331. The magnets 10340 are fully encased in the samematerial as the lower arms 10330. In an example, the magnets' enclosurein the lower arms may be provided by overmolding or ultrasonic welding,for example. The magnets 10340 are magnetically attracted to a magnet10216 embedded in a headgear clip 10210 e.g., by polar attraction. Theheadgear clip 10210 is positioned on and freely movable along the bottomheadgear straps 10220 of the positioning and stabilising structure 3300.FIG. 109 shows a cross-section of the headgear clip 10210 and the magnet10216 embedded therein. As illustrated, the headgear clip 10210 providesa cross-bar 10218 defining a slot or void 10217 that allows the headgearstrap 10220 to be threaded therethrough. In an example, the slot 10217is elongate having its longitudinal axis oriented parallel with anominal vertical axis in use. When the headgear clip 10210 is engagedwith the headgear connection point 10331 and headgear tension isapplied, the slot 10217 is unobstructed by the lower arm 10330 and frame3310.

The magnetic attraction between magnets 10340 and magnets 10216 guideand align the headgear clip 10210 to the lower headgear connectionpoints 10331 of the lower arms 10330. They may also assist with providesome engagement force of the headgear clip 10210 to the frame 3310 atthe lower headgear connection points 10331 in addition to the mechanicalengagement of the headgear clip 10210 with the lower headgear connectionpoints 10331. In an example, the headgear clip 10210 and frame 3310 mayform a sub-assembly referred to as a headgear system.

The magnet 10216 is fully covered by the material forming the headgearclip 10210. The material covering the magnets 10216 may have asubstantially smooth outer surface without having any mold lines.Similarly, the magnet 10340 is also fully encased in the lower arms10330. The material covering the magnets 10340 may have a substantiallysmooth outer surface without having any mold lines. In addition to beingvisually and aesthetically pleasing, the substantially smooth outersurface of the material covering the magnets 10216, 10340 minimise anyrelative friction and physical obstruction, thereby permitting easyrelative rotation.

Referring to FIG. 70, the headgear clip 10210 may comprise a mechanicalstructure or mechanical retention member 10215 adapted to mechanicallyengage with the lower headgear connection points 10331 of the lower arms10330 of frame 3310. The lower arms 10330 comprise magnets 10340 forreleasably retaining the bottom headgear straps 10220 with the lowerarms 10330. In one example, the mechanical retention member 10215 is aretaining wall or a raised wall, edge or rim in the shape of semi-circle(e.g., see semi-circular cross-section or U-shape of raised wall inFIGS. 70 and 109) to mechanically engage with a semi-circular peripheralregion of a cylindrical portion 10334 (e.g., see FIGS. 57 and 59) of thelower headgear connection point 10331. That is, the encasement of themagnet 10340 provides a raised surface 10335 via the cylindrical portion10334 extending anteriorly, and the raised surface 10335 enables amechanical engagement to a circumferential raised edge 10215 of theheadgear clip 10210. This is a mating relationship where the male partis the semi-circular peripheral region of a cylinder or cylindricalportion 10334 at the lower headgear connection point 10331 (see FIG. 56)that mates with a female part which is the circular space defined withinthe raised edge 10215 of the headgear clip 10210 (see FIG. 70), i.e.,raised wall or edge 10215 defines a space adapted to receive theheadgear connection point 10331. This geometry provides a snug fit ormechanical lock between the female part and male part. For example, themechanical structure prevents linear displacement of the headgear clip10210 in a direction substantially parallel to the Frankfort horizontaldirection when headgear tension is applied. In an example, the raisedsurface 10335 via the cylindrical portion 10334 may be angled or slopedto provide an undercut to facilitate retention of the headgear clip10210 on the cylindrical portion 10334. The circular mating geometryalso allows for 360° rotation of the headgear clip 10210 relative to theheadgear connection point 10331, with the shear force corresponding tothe magnetic force between magnets 10216, 10340. That is, the magnet10340 and the raised surface 10335 provided by the cylindrical portion10334 of the lower headgear connection point 10331 have a substantiallycircular or oval cross-section which enables the headgear clip 10210 andits raised edge 10215 to rotate relative to lower arm 10330 whenmagnetically engaged, e.g., to minimize the lower headgear strap 10220from twisting when headgear tension is applied. For example, whenheadgear tension is applied by adjusting the length of the headgearstrap 10220, the headgear clip 10210 maintains mechanical and magneticengagement with the lower arm 10330 and rotates relative to the lowerarm 10330. The magnets 10340 may be fully encased such that they arecompletely covered on all surfaces by a thin layer of plastic material.This may be the same plastic material forming the lower arms 10330 andis therefore seamless, visually aesthetic and integrally formed. Themagnets 10340 of the lower arms 10330 magnetically attract the headgearclip 10210 to guide and position the headgear clip 10210 to a specificposition on the lower arms 10330 in use. The lower arms 10330mechanically engage the headgear clip 10210 using the matingrelationship described earlier to maintain a reliable mechanicalengagement until intentionally released by the patient 1000. FIG. 112also shows the magnetic and mechanical engagement between the lower arm10330 and the headgear clip 10210, with the raised edge 10215 of theheadgear clip 10210 engaged with the raised surface 10335 of thecylindrical portion 10334 of the lower arm 10330.

An exemplary advantage of the magnetic headgear engagement according toan example of the present technology is that the headgear clip 10210includes a lower profile, e.g., leading to less bulk, less physicalobstruction, less weight, and more visual appeal. Another exemplaryadvantage is improved usability, e.g., the direction of thedisengagement force to detach the headgear clip 10210 from the lower arm10330 is low in certain directions, but high in other directions. Thisarrangement prevents accidental disengagement in use but allows easyintentional disengagement. Another exemplary advantage is accurateguiding of the headgear clip magnet 10216 to the lower arm magnet 10340due to the shape and mating geometry of the headgear clip 10210 and thecylindrical portion 10334 of the lower arm 10330, i.e., the planarsurfaces of the magnets 10216, 10340 will substantially align againsteach other concentrically (e.g., see FIG. 112), when the magneticattraction force pulls them together at a certain distance apart.

In another example, the circumferential raised edge of the retentionmember 10215 may have a notch, which allows the clip to be used forother masks where rotation is not desired, e.g., an oro-nasal mask. Aheadgear connector point in such oro-nasal mask would have a protrusionto engage the notch and therefore prevent relative rotation.

When the headgear clip 10210 is magnetically engaged with the magnet10340 of the lower arm 10330, at the inner surface of the mask 3000, themagnetic field strength at the surface of an assembled headgear clip10210 and frame 3310 is less than 380 millitesla (mT) as measured by aGauss meter or magnetometer. The magnetic field strength may be about160 mT to about 190 mT. The magnetic field strength may be about 180 mT.Due to ICNIRP Guidelines on Limits of Exposure to Static Magnetic Fieldspublished in: Health Physics 96(4):504-514; 2009, the magnetic fieldstrength should not exceed 400 mT. Also, if the magnetic field strengthis too strong, it may be difficult for the patient 1000 to easily detachthe headgear clip 10210 from the lower arm 10330. If the magnetic fieldstrength is too weak, then accidental detachment of the headgear clip10210 from the lower arm 10330 may become frequent and the guiding andalignment function of the co-operating magnets 10340, 10216 may besignificantly diminished and lack benefit for the patient 1000. In anexample, the magnets 10216, 10340 may be a ferromagnetic material,permanent magnet, or electromagnet.

The headgear clip 10210 is self-locating from the magnetic attractionwith the lower arm 10330, which is non-visually helpful, e.g., in adarkened room, particularly by elderly and arthritic patients. Also, theheadgear clip 10210 provides audible and tactile feedback to indicatesuccessful mechanical engagement with the lower arm 10330. The magnets10216, 10340 guide orientation are not solely for maintaining engagementbetween the lower arm 10330 and headgear clip 10210. When headgeartension is applied by tightening the headgear straps 3301, themechanical engagement between the headgear clip 10210 and lower arm10330 prevents the headgear clip 10210 disengaging from the lower arm10330. Although two magnets have been described, it may be possible forthere to be one magnet (clip 10210 or lower arm 10330) and one ferritematerial (clip 10210 or lower arm 10330).

The Mojo® full face mask manufactured by Sleepnet Corporation comprisesmagnetic headgear connectors and an adjustable forehead support. TheMojo® mask has a cushion filled with gel permanently connected to arelatively rigid shell of the mask. A vented swivel elbow extends fromthe shell. A pair of magnets is housed in the shell proximal to thelateral sides of the shell. A central region of each magnet is exposedto the environment on its top and bottom surfaces and is not covered byany plastic material. Similarly, the magnet in each triangular shapedheadgear clip is also exposed to the environment on its top and bottomsurfaces. In contrast, the magnets of the present technology are fullyencased or encapsulated in a plastic material, i.e., see FIGS. 109 and112 showing magnet 10216, 10349 held within clip 10210/lower arm 10330by a top layer of plastic material and a bottom layer of plasticmaterial, e.g., with the raised wall 10215 projecting away from thebottom layer of plastic material (e.g., raised wall 10215 projects froma circumferential portion around the magnet 10216), which minimises orprevents damage to the magnets caused by scratching and prevents contactwith ambient air to avoid oxidisation or corrosion. The magnets 10340 inthe lower arms 10330 of the frame 3310 of the present technology arespaced further apart than the magnets in the shell of the Mojo® mask.The magnets in the shell of the Mojo® mask can only be spaced apart bythe maximum width of the shell, which is less than the maximum width ofthe cushion. In contrast, the magnets 10340 in the lower arms 10330 ofthe frame 3310 of the present technology are spaced further apart thanthe maximum width of the cushion assembly 3002. This positioning andlocation makes it easier for the patient 100 to attach and detach theheadgear clip 10210 from the lower arm 10330 of the frame 3310. Also, itimproves the lower headgear tension vector LV to be closer aligned withthe Frankfort horizontal direction and therefore the headgear tension ismore evenly distributed on the patient's face without concentration inspecific facial areas. This also improves the stability of the mask1000.

In the Mojo® mask, the headgear clip magnetically engages with themagnets in the shell. When the headgear clip is magnetically engagedwith the magnets in the shell it is unable to rotate because aprotrusion extending outwardly from the shell projects through a voiddefined in the headgear clip which is also used by the headgear strap toloop through. In contrast, the headgear clip 10210 of the presenttechnology is able to rotate 360° when magnetically engaged with themagnet 10340 in the lower arm 10330 of the frame 3310. Rotation of theheadgear clip 10210 for a nasal mask improves comfort and stability dueto different facial and head shapes and sizes of patients 1000. It mayalso reduce the likelihood of accidental disengagement of the headgearclip 10210 if the patient 1000 moves while asleep because it is able torotate if the headgear strap 10220 is pulled in a different direction.Also, the protrusion of the shell and the triangular shaped headgearclip of the Mojo® mask makes it difficult to disengage the headgear clipfrom the shell because it requires the patient to first lift or tilt theheadgear clip up to clear the protrusion. In contrast, the headgear clip10210 of the present technology is able to detach from the lower arm10330 by an outwardly twisting motion by holding onto the end of theheadgear clip 10210 opposite the mechanical retention member 10215 nearthe cross-bar 10218 and disengage the magnets 10340, 10216.

The width of the void 10217 in the headgear clip 10210 of the presenttechnology is also wider than the void in the headgear clip of the Mojo®mask by at least double. This means that the bottom headgear strap 10220of the positioning and stabilising structure 3300 of the presenttechnology is able to move relatively easier through the void 10217 whenadjusting the headgear strap length as there is less friction and morespace between the headgear strap 10220 and the headgear clip 10210compared to the Mojo® mask. This enables the patient 1000 to quickly andconveniently adjust the headgear tension of the patient interface 3000for optimum comfort and stability without much frustration from theheadgear strap 10220 not moving smoothly and freely through the headgearclip 10210.

During therapy, a patient's head may turn from side to side or up anddown during sleep. For patient interfaces 3000 used by patients 100 whensleeping, the strap and seal arrangement should also accommodateunconscious or reflexive head and body movements. If it does not,treatment is compromised and the patient 1000 is ill served by thepatient interface 3000. The magnets 10216, 10340 can be simultaneouslyfastened or released. As a result of the substantially identicaldimensions of the complementary magnetic coupling surfaces of themagnets 10216, 10340, the magnets 10216, 10340 will come intosubstantially automatic alignment once they come into contact and noexternal help is therefore required in general for the initial contactand the subsequent engagement. Since the coupling surfaces of themagnets 10216, 10340 having opposite or complementary magneticpolarities and since magnetic coupling forces are usually strongest inthe direction which is substantially normal or perpendicular to thecoupling surfaces, the mutual lateral attraction is relatively weak andlateral dislocation of the magnets 10216, 10340 may occur relativelyeasily by lateral pulling of the magnets 10216, 10340 which may causeinadvertent or accidental disengagement of the fasteners when a lateraltension is applied. Therefore to retard undesirable lateral movement,the mechanical retention member 10215 has been provided for the headgearclip 10210. They be separated simply by pulling the headgear clip 10210and lower arm 10331 apart and moved away from each other. They areautomatically fastened when the magnets 10216, 10340 are in proximity ofeach other.

The magnets 10216, 10340 are completely enclosed and are preferablywater-tight or air-tight to minimise or eliminate the possibility of themagnet 10216, 10340 oxidising or corrosion which may lead todemagnetisation or deterioration. The enclosure of the magnets 10216,10340 provides a cosmetic cover to protect the magnets 10216, 10340 fromthe environment and ensure that they maintain their original visualappeal which is important for product presentation and appearance. In anexample, the magnets 10216, 10340 may include a coating (e.g., magnets10216, 10340 coated with nickel or zinc), e.g., to preventscratching/damage to the magnet.

In one example of the present technology, multiple headgear straps 3301are used that are fully length adjustable (upper and lower straps 10220,10230) to accommodate the various head sizes of patients 1000. Patients1000 may often tighten the straps 3301 a little too much to try tocounteract rotational forces typically caused by the patients 1000involuntarily turning their heads from side-to side or up and downduring sleep. Some prior magnetic clasps unrelated to patient interfacesfor CPAP therapy are not designed to counteract rotational forces of themagnitude encountered by patients 1000 having involuntary movements oftheir heads. Also, some headgear straps of prior masks cannot betightened sufficiently to fit all patients 1000. However, in the presenttechnology, the magnetic headgear clip 10210 together with the magneticlower arm 10330 when used with multiple headgear straps 3301 is fullyadjustable to accommodate the various head sizes of patients 1000 andare able to counteract rotational forces typically caused by patients1000 involuntarily turning their heads from side-to side or up and downduring sleep. In an example, only two headgear sizes may be provided toprovide a wide headgear fit range to cover nearly all patients. However,it should be appreciated that more or less headgear sizes are possible.

In an alternative example, the upper arms 10320 may comprise magnetsenclosed or embedded in a distal free end 10323 of the upper arms 10320at the upper headgear connecting points 10325.

Vent 3400

In one form, the patient interface 3000 may include a vent 3400constructed and arranged to allow for the washout of exhaled air(including exhaled carbon dioxide). The vent 3400 is not bulky. The vent3400 directs exhaust air away from the frame 3310.

Referring to FIG. 78, one form of vent 3400 in accordance with thepresent technology comprises a plurality of very small holes 3405 (e.g.,see FIGS. 106 and 114), in other words, a multi-hole vent. Two or moremulti-hole vents 3400 may be provided on the frame 3310.

In an example, the exhaust vent 3400 is integrated into the frame 3310and is implemented as an array of at least thirty (30) vent holes, e.g.,at least 40 vent holes 3405, that ring around the short tube cuff 10610adjacent to the connection port 3600. In other words, the vent 3400 hasa substantially circular shape. That is, the ring member 10315 has amulti-hole vent 3400 radially disposed around the connection port 3600for connection to the air circuit. The individual vent holes 3405 areshaped so as to diffuse the exhaust air (i.e., not directional) therebyreducing the exhaust noise and effects of “air jetting”, whilstproviding adequate CO₂ washout. This diffused vent 3400 is intended tominimize sleep disturbances to both the patient 1000 and their bedpartner 1100. When the cushion assembly 3022-1 is removed, the frameside of the dead-space can be accessed for cleaning. Hence the ventholes 3405 can be cleaned from both sides.

The vent 3400 has a hole area of 0.317 mm², an inlet vent gap of 2.9 mmand the diameter of the vent ring is 34.7 mm. If the vent 3400 has 60holes and the flow rate at 20 cm H2O is 59 litres per minute. If thevent 3400 has 41 holes and the flow rate at 20 cm H2O is 45 litres perminute.

The angle of the diffused airflow can be tuned by altering thedimensions of the vent holes. The diffused airflow provides venting overa larger area to avoid jetting and may also reduce noise. Spaced-aparttracks may be proximate each vent hole. The tracks are generallyrectangular. However, the tracks may have other suitable shapes todirect washout gas, e.g., elliptical. In an example, the arrangement ofthe tracks may also incorporate the use of an annular baffle.

For example, as shown in FIGS. 106, 111, 113, and 114, the ring member10315 of the frame 3310 includes an outer radial wall 10350 and an innerradial wall 10351, both of which project posteriorly along theconnection port 3600. The radial walls 10350, 10351 define a radialchannel 10352 leading to the vent holes 3405. As noted above,spaced-apart tracks 10355 extend radially inwardly from the outer radialwall 10350 to direct exhaled air from the patient to the vent holes3405.

In an example, the short tube cuff 10610 of the tube 4180 may beconnected, e.g., permanently connected, to the ring member 10315 of theframe 3310 via a mechanical interlock. For example, as shown in FIGS.106, 107, and 108, the cuff 10610 includes an annular groove or recess10611 that is structured to receive an annular rib 10360 provided to theinner radial wall 10351 (e.g., see FIG. 114), which allows the cuff10610 to mechanically interlock with the inner radial wall 10351. Asillustrated, at least one of the interior side surfaces of the recess10611 may include a sloped configuration, e.g., to facilitate interlock,molding. As best shown in FIGS. 106 and 114, the inner radial wall 10351includes a radially inwardly extending stop surface 10353 that providesa stop to prevent the cuff 10610 from inserting further onto the frame.In addition, the stop surface 10353 provides an indication that the cuff10610 and hence the tube 4180 is fully attached to the frame 3310. In anexample, the cuff 10610 is non-rotatably connected to the ring member10315 of the frame 3310 via the inner radial wall 10351.

In an example, the cuff 10610 of the tube 4180 may be insert molded tothe frame 3310 to provide a permanent and non-rotatable connection.Alternatively, the mechanical interlock may be a one way snap fitbetween the cuff 10610 and the frame 3310.

In use, as shown in FIG. 106, the inner radial wall 10351 projectsposteriorly to function as a baffle and segregate the flowpath ofincoming pressurised air from the PAP device from the flowpath ofexhaust via the vent 3400 to reduce cyclic noise. In an example, thecuff 10610 may project sufficiently posteriorly to facilitate thesegregation of air flowpaths (incoming pressurized air from PAP device4000 and exhaled air from the patient) along with the inner radial wall10351.

Connection Port 3600

Connection port 3600 allows for connection of the patient interface 3000to a short tube 4180 of the air circuit 4170, as shown in FIG. 83. Inone example of the present technology, the short tube 4180 may beconnected directly to the patient interface 3000 by the connection port3600. The short tube 4180 may be connected to the frame 3310 at theconnection port 3600 by insert molding the frame 3310 onto the shorttube 4180, in particular onto the short tube cuff 10610. The connectionport 3600 may be located on the patient interface 3000 and may provideeither a fixed or movable connection to the gas delivery tube 4180.

The connection port 3600 may be part of the frame 3310 such that theframe 3310 is molded to include the connection port 3600 in one piece.Additionally, the connection port 3600 may be connected to the frame3310 at a limited portion or portions of its periphery. This may resultin open areas between the connection port 3600 and the frame 3310 andthese open areas may include the vent(s) 3400 described herein. Theconnection port 3600 may be angled in any direction and at any anglerelative to the frame 3310. The connection port 3600 may be angleddownward relative to the frame 3310 to cater for a majority of patientswho typically have the tube 4180 directed downwards during treatment.This minimises looping of the tube 4180 and may improve seal andstability of the patient interface 3000 during treatment. It may also bepossible to form the connection port 3600 separately from the frame 3310and connect these components such that the connection port 3600 mayrotate relative to the frame 3310 using a swivel connection. In such anexample, may improve reduce tube torque of the short tube 4180disrupting sealing forces, or may improve comfort and seal if the shorttube 4180 is configured in a tube-up position up over the patient'shead.

It should also be understood that the flow of gas into the patientinterface 3000 may be more evenly distributed in the example of thetechnology where no elbow is used to connect the air circuit 4170 to thepatient interface 3000. The sharp bend of an elbow may cause a largedensity of the flow lines on one side of the elbow. This may inducejetting where the flow is condensed and this may result in a suboptimalflow into the patient interface 3000 and, specifically, the seal-formingstructure 3100. It should also be understood that the vent 3400,described above, may contribute to the reduction in jetting. While theuse of elbows in prior masks have been to decouple tube torque byallowing at least relative rotational movement between the air circuit4170 and the frame 3310, one form of the present technology has aparticularly floppy short tube 4180 that is capable of decoupling tubetorque that conventional elbows would be responsible for.

Forehead Support

In one form of the present technology, patient interface 3000 does notinclude a forehead support. In one form, the patient interface 3000provides sufficient stability that a forehead support is not requiredwhich leads to less obtrusiveness and opens up the eyes and nasal bone.

In one alternative form, the patient interface 3000 includes a foreheadsupport.

Anti-Asphyxia

In one form of the present technology, patient interface 3000 mayinclude an anti-asphyxia valve (AAV). In further examples of the presenttechnology, when a full-face mask is used an AAV may be included withthe decoupling structure 4190 (see FIG. 1 b), the air circuit 4170 (seeFIGS. 1 a to 1 c), or the patient interface 3000.

Ports

In one form of the present technology, patient interface 3000 mayinclude one or more supplemental oxygen ports 4185 that allow access tothe volume within the plenum chamber 3200. In one form this allows aclinician to supply supplemental oxygen. In one form this allows for thedirect measurement of a property gases within the plenum chamber 3200,such as the pressure.

Decoupling Structure(S) 4190

In one form, the patient interface 3000 includes at least one decouplingstructure, for example, a rotatable cuff or adapter 4190, as shown inFIGS. 1 b and 1 c, or a ball and socket. Referring to FIGS. 1 b and 1 c,decoupling of a tube-drag force is provided at least in part by shorttube 4180. In this way, short tube 4180 functions at least in part as adecoupling structure 4190.

Referring to FIGS. 1 b and 1 c, at an end of the short tube 4180 is therotatable cuff or adapter 4190 to facilitate connection to a third endof an additional gas delivery tube 4178 that may be different in atleast one aspect from the short tube 4180. The rotatable cuff 4190allows the short tube 4180 and the additional gas delivery tube 4178 torotate relative to one another at respective ends. The additional gasdelivery tube 4178 may incorporate similar features to the short tube4180, but may have a larger inner diameter (e.g., 18 mm-22 mm). Thisadditional degree of freedom provided to the tubes may help to reducetube drag forces by alleviating twisting, and therefore kinking, of theair circuit 4170. Another end of the additional gas delivery tube 4178may be connected to a PAP device 4000.

Short Tube 4180

In one form of the present technology, a short tube 4180 is connected toframe 3310 at the connection port 3600 via a longer tube (additional gasdelivery tube) 4178 connected to the PAP device 4000, as shown in FIG.82. The short tube 4180 and forms part of the air circuit 4170.

The short tube 4180 is a gas delivery tube in accordance with an aspectof the present technology is constructed and arranged to allow a flow ofair or breathable gasses between the PAP device 4000 and the patientinterface 3000.

Gas delivery tubes are subject to tube drag forces which represent theforce subjected to the tube while in use as it lays on the patient andother surfaces (e.g., a bed, a nightstand, a hospital bed, a table,floor, etc) during use. Since the short tube 4180 is connected to thepatient interface 3000 to provide breathable gas to the patient 1000these tube drag forces can affect the connection between the patientinterface 3000 and the patient 1000. For example, tension and torsiontube drag forces may cause the patient interface 3000 to displace fromthe patient's face, thereby causing leakage of the breathable gas fromthe patient interface 3000. Thus, it is desirable to decrease the tubedrag forces. This may be accomplished by reducing the weight of theshort tube 4180, improving its flexibility (e.g., by decreasing its bendradius such that the tube 4180 can be curved more tightly), and addingat least one degree of freedom for the short tube 4180. Also, such areduction in tube drag forces must be accomplished without significantlyreducing the strength of the tube 4180 such that it may resist occludingforces, e.g., when a patient may lay his or her arm on the tube 4180 orwhen twisted into a kinked position.

FIGS. 4 to 6 show three side views of an exemplary short tube 4180 inthree different states. FIG. 4 shows the short tube 4180 in a neutralstate or normal condition. In the neutral state, the short tube 4180 isnot subject to any external forces, i.e., it is not stretched orcompressed. The short tube 4180 may be comprised of a web of material4172 that is spaced between adjacent coils of a helical coil 4174. Thehelical coil 4174 of the short tube 4180 may have a width of WC. The webof material 4172 may span the distance between adjacent coils WF.Further, as shown in FIG. 4, the web of material 4172 may be folded suchthat a vertex or peak of the fold 4182 extends radially outward frombetween adjacent coils. It should be understood that due to the fold4182 of the web of material 4172, the width of material comprising theweb of material 4172 may be wider than the width between adjacent coilsWF. Also, the web of material 4172 may be folded along a predeterminedfold line 4186.

Also shown in FIG. 4, the distance between adjacent coils WF may beequal, or substantially equal, to the width of the helical coil WC whenthe short tube 4180 is in the neutral state. In such an arrangement, themaximum bend radius R (shown in FIG. 7) of the tube 4180 is decreasedand flexibility is improved. This is because an amount of materialgreater than in prior art tubes must be used to span the distancebetween adjacent coils. For one, the distance WF being equal to thewidth of the coil WC results in a larger amount of material to span thedistance, and because it is folded an even greater amount of materialmust be provided to comprise the web of material 4172. This principle isdescribed in greater detail in relation to FIG. 7. The shape of the fold4182 is important to the overall flexibility of the tube 4180. A largerradius in the folds 4182 of the web produces a more flexible tube 4180.A very sharp crease makes the tube 4180 less flexible. After multiplethermal disinfection cycles, the folds 4182 start to relax and the tube4180 becomes less flexible. When the fold 4182 is relaxed, it isobserved that the fold diameter is reduced relative to the coil diameterand hence the peaks 4186 of the folds 4182 are lowered.

Additionally, in FIG. 4 it can be seen that the fold of the web ofmaterial 4172 extends not only radially outward from the short tube4180, but the fold of the web of material 4172 is centrally locatedbetween adjacent coils of the helical coil 4174. Furthermore, FIG. 4also shows how the slope of the web of material 4172 may increasetowards the vertex or peak of the fold 4182 from adjacent coils of thehelical coil 4174. In other words, the web of material 4172 is flatterfurther away from the predetermined fold line or peak 4186 and the webof material 4172 becomes steeper and pointier near the vertex or peak4186 of the fold 4182.

Also in FIG. 4, as will be discussed in greater detail below, it can beseen that an outer portion or outer surface 4184 of the helical coil4174 has a curved profile that is rounded over a wide angle. In otherwords, the helical coil 4174 may have a profile of a portion of theperimeter of an oval. By providing a rounded outer surface or profile4184 to the helical coil 4174, a softer and smoother tactile feel may beprovided to the patient 1000. Additionally, this rounded outer surface4184 may also decrease the propensity of the short tube 4180 to snag onsurfaces while in use, such as bedding, the patient's clothing, bedroomor hospital furniture, etc. As can been in FIG. 4, a coil diameter DCcan be seen, which is the diameter of one of the plurality of helicalcoils 4174 measured perpendicularly to the longitudinal axis of theshort tube 4180.

Another feature that may be seen in FIG. 4, the short tube 4180, in itsneutral state, has the fold 4182 of the web of material 4172 risingradially outward from the gas delivery tube 4180 such that the vertex orpeak of the fold 4182 is at substantially the same height, or the sameheight, as the outer surface 4184 of the helical coil 4174. The fold4182 of the web of material 4172 also defines a fold diameter DF betweenopposite vertices of the fold 4182 measured perpendicularly to thelongitudinal axis of the short tube 4180. Said in another way, when theshort tube 4180 is in its neutral state, the diameter of the web ofmaterial 4172 spanning respective vertices of its fold 4182 across thelongitudinal axis of the gas delivery tube 4180 may be equal to thediameter of the helical coil 4174 spanning respective outer surfaces4184 across the longitudinal axis. It could also be said that if theshort tube 4180 is laid out straight in a neutral state, that a singlecylinder could be circumscribed flush to the vertex or peak of the fold4182 and the outer surface 4184 of the helical coil 4174. Also, it maybe said that when the short tube 4180 is in a neutral state that thefold diameter DF is equal to, or substantially equal to, the coildiameter DC.

Such an arrangement, in conjunction with the rounded outer profile 4184of the helical coil 4174, may provide an improved tactile feel, makingfor a smoother and softer feel for the patient. Additionally, the shorttube's 4180 decreased propensity to snag may also be enhanced by havingthe vertex or peak 4186 of the fold 4182 and the outer surface 4184 ofthe helical coil 4174 rise to the same height because there is no singlesurface that protrudes prominently to snag on external surfaces.

In another example of the present technology, the web of material 4172may be folded multiple times in between adjacent coils of the helicalcoil 4174. This may allow for additional flexibility of the short tube4180 along with further extensibility due to the additional amount ofmaterial that is between each adjacent coil. Also, in another example ofthe present technology there may be certain regions or portions alongthe length of the short tube 4180 where the web of material 4172 isfolded between adjacent coils of the helical coil 4174 and other regionsof the gas delivery tube where the web of material is not folded. Suchan arrangement may allow for varying degrees of flexibility andextensibility along the length of the gas delivery tube. For example, itmay be possible to provide portions of the short tube 4180 withincreased or decreased stiffness at locations near the patient interface3000 and the PAP device 4000. In one example, portions of the short tube4180 near the patient interface 3000 and the PAP device 400 may havefewer folds per unit length of tube 4180 to increase the stiffness ofthe tube 4180 in these regions so as to ensure that kinking is reducedin these regions. Another reason not to fold a section of web ofmaterial 4172 could be for manufacturing reasons. For example, nothaving a fold 4182 on the web 4172 at the distal ends where overmoldingof a cuff 10610, 4190 is to occur. This may reduce the tendency ofcreating a weak spot in the web 4172 where it joins the cuff 10610, 4190as a folded web at these locations can get caught in a weak pinchedstate.

FIG. 5 shows another side view of the exemplary short tube 4180. In thisview, the short tube 4180 is in a compressed or contracted state. Inthis state, the length of the short tube 4180 will be less than itslength when it is in the neutral state shown in FIG. 4. For example, theshort tube 4180 may be compressed to a length that is up to 50% lessthan in the neutral state. When the short tube 4180 is compressed to itscompressed state the web of material 4172 is compressed such that itsfold 4182 becomes steeper and the distance between adjacent coils WF ofthe helical coil 4174 decreases. In the compressed state, the distancebetween adjacent coils WF may decrease to less than the width of thehelical coil WC. Also, the vertex or peak 4186 of the fold 4182 of theweb of material 4172 may be forced further outward in the radialdirection such that the vertex or peak rises above the outer surface4184 of the helical coil 4174. In other words the web of material 4172may become taller. This effect may be controlled by the amount ofmaterial between adjacent coils WF and the angle of the fold and thethickness TW of the web of material 4172. Moreover, it should also beunderstood that while the width of the helical coil WC may not decreaseduring compression of the short tube 4180, the adjacent coils of thehelical coil 4174 may be forced together as is common with othersprings. Also in FIG. 5, it can be seen that when the short tube 4180 isin the compressed state the angle at the vertex or peak 4186 of the fold4182 of the web of material 4172 (i.e., the angle between each portionof the web of material 4172 on either side of the predetermined foldline) is decreased and, again, the web of material 4172 may becometaller.

FIG. 6 shows an additional side view of the short tube 4180 when it isin its extended or elongated state. In this state the short tube 4180may have a length greater than in the neutral state shown in FIG. 4. Forexample, the short tube 4180 may be extended up to 200% of its lengthwhen in the neutral state. Also, in this view it can be seen that thedistance between adjacent coils WF of the helical coil 4174 increasesand the fold 4182 of the web of material 4172 becomes flatter. Also, thedistance between adjacent coils WF may increase to greater than thewidth of the helical coil WC. Further, in FIG. 6 it can be seen that thevertex or peak of the fold 4182 of the web of material 4172 may beforced radially inward such that the vertex or peak 4186 descends tobelow the height of the outer surface 4184 of the helical coil 4174.Again, this may be controlled by the amount of material between adjacentcoils WF and the angle of the fold 4182. Moreover, it should also beunderstood that while the width of the helical coil WC may not increaseduring extension of the short tube 4180, the adjacent coils of thehelical coil 4174 may be forced apart as is common with other springs.Also in FIG. 6 it can be seen that when the short tube 4180 is in theextended state, the angle at the vertex or peak of the fold 4182 of theweb of material (i.e., the angle between each portion of the web ofmaterial on either side of the predetermined fold line) is increasedand, again, the web of material 4172 may become flatter.

FIG. 7 shows an exemplary short tube 4180 curved between two ends. Whencurved as shown in FIG. 7, the web of material 4172 between adjacentcoils of the helical coil 4174 may be extended at the outer side of thecurved portion 4179 and the web of material at the inner portion of thebend 4176 may be compressed. When curved such as this, the limits of thebend radius R may be better understood. In one example, when draped overa cylinder having a 13 mm diameter, the tube may have a bend radius R of44 mm under its own weight (i.e., with no additional weight applied).The greater the amount of material that comprises the web of material4172 the lower the possible bend radius R because, as can be seen inFIG. 7, the outer side of the curved portion 4179 can only be extendedup to the maximum possible distance between adjacent coils WF. At theouter portion of the bend 4179 the short tube 4180 can only bend andextend, at that outer portion 4179, up to the width of the web ofmaterial 4172 provided between adjacent coils WF. Thus, if more materialis provided for the web of material 4172 between adjacent coils WFflexibility is improved because the short tube 4180 can be flexed suchthat the outer portion of the bend 4179 is extended further and themaximum bend radius R is decreased.

Also, it can be seen that the distance between adjacent coils WF at theinside of the curved inner portion of the bend 4176 is decreased to thepoint that adjacent coils WF of the helical coil 4174 are nearlytouching. Therefore, the bend radius R is also limited by the web ofmaterial 4172 at the inner portion of the bend 4176. As can be seen inFIG. 8, the web of material 4172 is compressed between adjacent coils ofthe helical coil 4174 at the inner portion of the bend 4176. Thus, thethicker the web of material 4172 the greater the maximum bend radius Rbecause the greater the amount of material between adjacent coils WF,the less they are able to approach one another at the inner portion ofthe bend 4176.

Therefore, to optimize the bend radius R of the short tube 4180 asufficient width of the web of material 4172 must be provided to allowthe outer portion of the bend 4179 to extend to meet the desired bendradius, but also a sufficient thickness of the web of material 4172 mustbe provided to allow adjacent coils WF of the helical coil 4174 to cometogether at the inner portion of the bend 4176 to achieve the desiredbend radius.

FIG. 8 shows a cross-sectional view of an exemplary short tube 4180taken as shown in FIG. 7. This cross-sectional view of the short tube4180 shows the gas delivery tube 4180 in its neutral state such that thedistance between adjacent coils WF is equal to the width of the helicalcoil WC. The short tube 4180 may also have an internal diameter DI thatis about 18 mm. The short tube 4180 may have a pitch P of between 3.2 mmto 4.7 mm, or preferably 4.5 mm to 4.7 mm. This view also shows that thehelical coil 4174 may have greater thickness TC than the thickness TW ofthe web of material 4172. With the helical coil 4174 being thicker thanthe web of material 4172, the helical coil 4174 is able to providestructural strength and this gives the short tube 4180 a spring effect.Also in this view, it can be seen that the web of material 4172 may havea substantially uniform and/or continuous thickness.

FIG. 8 also shows that at least a portion of the web of material 4172may be asymmetrical about the predetermined fold line 4186. For example,the web of material 4172 may include a humped portion 4181 adjacent tothe helical coil 4174 on one side of the predetermined fold line 4186and a slanted portion 4183 may be included on the other side adjacent tothe other side of the helical coil 4174. Also, the slope of the web ofmaterial 4172 to the vertex or peak 4182 of the fold may be steeper onthe side of the slanted portion 4183 than on the side of the humpedportion 4181. Due to the different steepnesses, when the short tube 4180is in the neutral state, the width WFS between the edge of the helicalcoil 4174 on the side of the slanted portion 4183 and the predeterminedfold line 4186 may be less than the width WFF between the edge of thehelical coil 4174 on the side of the humped portion 4181 and thepredetermined fold line. Thus, when extended, the web of material 4172may be extended such WFS may increase more than WFF because a greateramount of material is comprised in that region. In other words, theshort tube 4180 may be extended a certain amount in a first direction(e.g., from the slanted portion 4183 to the humped portion 4181) and adifferent amount in a second direction opposite the first direction(e.g., from the humped portion to the slanted portion). Such anarrangement may be advantageous where the patient interface 3000 isattached to the short tube 4180 at one end and the PAP device 4000 atthe other, because the patient 1000 may move while wearing the patientinterface 3000, thus necessitating a greater amount of extensibility inthe direction of the patient 1000. The asymmetric profile of the tube4180 is typically a result of how the tube 4180 was made. Alternativelythough, it may also be possible for the web of material 4172 to havesubstantially symmetrical profile about the predetermined fold line4186.

The width of the humped portion WH and the width of the slanted portionWS may be different as can be seen in FIG. 8. Thus, the web of material4172 may be flexed over a greater range toward the adjacent coil WFacross the slanted portion 4183 than across the humped portion 4181. Inother words, due to the larger gap at WS a greater amount of flexibility(i.e., smaller bend radius) may exist in this particular region than atWH, which has a smaller gap. Also, because of the smaller gap at WH thisportion may be compressible to a lesser extent than at WS, because theweb of material 4172 is already closer to the coil 4174 at WH than atWS.

Another feature shown in FIG. 8 is that the superficial surface area(e.g., the outermost surface area of the short tube 4180) may becomprised in a greater proportion by the outer surface 4184 of thehelical coil 4174 than the web of material 4172 if the helix coil 4174generally feels better than the web 4172, particularly if the folds inthe web 4172 are very sharp. This may provide a better tactile feel forthe patient because, as can be seen in FIG. 8, the outer surface 4184 ofthe helical coil 4174 is rounded and therefore smoother than the vertexor peak of the fold 4182 of the web of material 4172.

Also it can be seen in FIG. 8 that the web of material 4172 and thehelical coil 4174 may be integrally bonded so that the interior surfaceof the short tube 4180 is smooth and continuous. It should be understoodthat either adjacent sides of the web of material 4172 may be joined toone another to form the smooth and continuous interior surface or theweb of material 4172 may be bonded to adjacent sides of adjacent coilsof the helical coil 4174. By forming the short tube 4180 in this manner,such that the interior surface is smooth and continuous, a smoother flowof breathable gas may be provided through the gas delivery tube 4180.Typically, the folds 4182 are formed after the overmolding of the cuffs10610, 4190 on both ends of the short tube 4180 to prevent tape pinch.

It should also be understood that any suitable combination of materialsmay comprise the web of material 4172 and the helical coil 4174. Thematerials of each respective component 4172, 4174 may be the same orthey may be different in at least one aspect. In one example of thepresent technology, the web of material 4172 and the helical coil 4174may be made from a thermoplastic elastomer (TPE) or thermoplasticpolyurethane (TPU). The web 4172 and coil 4174 may both be made from thesame plastic material (or different blends of the same plastic material)which is advantageous to produce an integral chemical bond (molecularadhesion) between the web 4172 and the coil 4174. Material choices areconstrained by a number of factors. The mechanical properties of thematerial for the web 4172 for allowing flexibility are a decidingfactor. The ability to withstand thermal disinfection is anotherimportant factor. Not being sticky and tacky are other factors. Also,the short tube 4180 must avoid occlusion and withstand hoop stress whenan external force is applied on the circumferential surface of the tube4180 which may occur if a patient's limb lies on top of the short tube4180. This is addressed by providing the short tube 4180 with a minimuminternal diameter, and specifying the helix pitch and structuralrigidity of the helical coil 4174.

The choice of materials may also affect the spring stiffness (P=kx,where P is load, k is stiffness and x is deflection) of the short tube4180. The stiffer the spring k, the smaller the deflection under aconstant load. The spring rate is the amount of weight required todeflect a spring (any spring) per measurement unit. For example,materials having different moduli of elasticity and different flexuralstiffness may be used for the web of material 4172 and the helical coil4174, respectively, to create the desired spring stiffness. Similarly,the spring stiffness may also be chosen by using a material with thesame modulus of elasticity for both the web of material 4172 and helicalcoil 4174. Also, the pitch of the helical coil 4174, as discussed inreference to FIG. 8, may also affect the spring stiffness of the gasdelivery tube 4180. In one example, the spring stiffness may be about0.03 N/mm.

FIG. 9 shows another view of an exemplary short tube 4180 in a bent orcurved state. In this view, similar to FIG. 7, the short tube 4180 iscurved over a radius R. However, in this view the short tube 4180 can beseen draped over the edge of a flat, elevated surface (e.g., a table) todemonstrate how the tube 4180 might bend when subjected to tension atone end due to gravity. The weight of the portion of the short tube 4180that hangs over the corner of the table may cause extension of the tube4180 and bending at a region of the tube 4180 near the edge of thetable. This view depicts similar bending characteristics to those shownin FIG. 7. Specifically, the web of material 4172 is extended at theouter side of the bent region 4179 and compressed at the inner portionof the bend 4176, such that WF is greater at the outside of the curvethan on the inside.

FIG. 82 shows an exemplary short tube 4180 attached directly to apatient interface 3000. In prior masks, the gas delivery tube isattached to a mask through a swivelling elbow. By redirecting the gasdelivery tube with a swivelling elbow at its junction with the patientinterface, prior art assemblies seek to reduce tube drag forces.However, the inclusion of a swivelling elbow adds weight and parts whichcan, in turn, mitigate the reduction of tube drag forces. Thus, inaccordance with the present technology, the short tube 4180 may bedirectly connected to a mask frame 3310. The short tube 4180 may beangled downwardly from the connection to the mask frame 3310, which mayalso contribute to reducing tube drag forces. The downward angle may befacilitated in part by the connection port 3600.

Referring again to FIGS. 1 b and 1 c, a short tube 4180 according to thepresent technology can be seen connecting a patient interface 3000 at afirst end. This connection may be the fixed connection described abovein relation to FIG. 82. In this example, a cuff 10610 is overmolded onthe first end of the tube 4180 which is then overmolded to acorresponding connection port 3600 defined in the patient interface3000. This example is elbow-less in the sense that there is no elbowbetween the tube 4180 and the mask frame 3310. In other examples, it ispossible for a swivel elbow to be positioned between the tube 4180 andthe mask frame 3310 to enable the swivel elbow and the tube 4180 tofreely rotate relative to the mask frame 3310. It should be understoodthat the patient interfaces 3000 shown in these views are shown indashed lines to indicate that a variety of different patient interfacesmay be connected to the short tube 4180. At a second end of the shorttube 4180 is a rotatable cuff, swivel cuff or adapter 4190 to facilitateconnection to a third end of an additional gas delivery tube 4178 thatmay be different from the short tube 4180 (See FIGS. 36 and 82). Therotatable cuff 4190 allows the short tube 4180 and the additional gasdelivery tube 4178 to rotate relative to one another at respective ends.The short tube 4180 provides integrated tubing with the swivel 4190providing 360° unimpeded movement to accommodate just about any sleepingposition.

The additional gas delivery tube 4178 may incorporate similar featuresto the short tube 4180, but may have a larger inner diameter (e.g., 18mm-22 mm). This additional degree of freedom provided to the tubes 4178,4180 may help to reduce tube drag forces by alleviating twisting,decoupling any tube drag forces experienced, and therefore kinking, ofthe short tube 4180. A fourth end of the additional gas delivery tube4178 may be connected to a PAP device 4000. A two part swivel that issnapped in is in-mold-assembled into the cuff 4190. Alternatively, a onepart swivel snapped on is possible.

Referring to FIGS. 10 to 29, the tube 4180 of the present technology iscompared to prior short tubes which have a helical coil. The comparisonindicates that the flexural stiffness or floppiness of the tube 4180 ofthe present technology is superior because it has a lower gram-force(gf) when the tube 4180 is stretched. The lower end of the tubes is heldin a fixed position such that the longitudinal axis of the tubescommences from an angle that is perpendicular to the direction of forcebeing applied to elongate the short tubes. In other words, the lower endof the short tube is held so that it is initially parallel and tangentto a horizontal surface (see FIGS. 10, 15, 20, 25). The upper end of theshort tubes is held by an Instron machine directly above the held lowerend of the short tube. The Instron machine stretches the short tubes bya distance of 30 mm in a series of steps from 0 to 30 mm, to 60 mm, to90 mm and to 120 mm, in a vertically upwards direction. The Instronmachine also measures the force in Newtons at each distance which maycorrespond to the spring stiffness of the short tube. A torque gauge andforce gauge (Torque Gauge RM No. MTSD05997 and Mecmesin Force Gauge RMNo, MFGX05996) are used to measure the grams-force at the fixed lowerend of the short tube at each distance the short tube is elongated.Since the tubes having different weights and lengths, at the initialposition, the Instron machine, torque gauge and force gauge are zeroed.By zeroing the measurement equipment in this manner, the measurementswould be independent of weight and length of each tube. A 1 cm grid isalso placed in the background to generally indicate the angle of theshort tube at each distance. The comparison shows:

Tube 4180 of Present Technology (FIGS. 10 to 14) Distance Grams-ForceNewtons Force 0 0 0  30 mm 0 0  60 mm 40 0.2 N  90 mm 80 0.58 N  120 mm140 2.2 N

ResMed ™ Swift FX ™ Nasal Pillows Mask tube (FIGS. 11 to 19) DistanceGrains-Force Newtons Force 0 0 0  30 mm 40 0.1 N  60 mm 120 0.32 N   90mm 320 1.1 N 120 mm 580 3.1 N

Philips Respironics ™ GoLife ™ Nasal Pillows Mask tube (FIGS. 20 to 24)Distance Grams-Force Newtons Force 0 0 0  30 mm 60 0.24 N  60 mm 160 0.4 N  90 mm 500 0.71 N 120 mm 2820  6.6 N

Philips Respironics ™ Wisp ™ Nasal Mask tube (FIGS. 25 to 29) DistanceGrams-Force Newtons Force 0 0 0  30 mm 20 0.04 N  60 mm 120 0.17 N  90mm 300 0.73 N 120 mm 480  1.4 N

The comparison above shows that the short tube 4180 of the presenttechnology only begins to experience tube torque between 30 mm and 60 mmelongation whereas the prior tubes already experience tube torque by 30mm elongation. At every distance measured, the prior tubes have asignificantly higher grams-force indicating that they are less floppyand have a higher flexural stiffness compared to the tube 4180 of thepresent technology. Therefore seal disruption as a result of tube torqueis less likely to occur with the tube 4180 compared to prior tubes.Also, the floppiness of the tube 4180 enables it to be directlyconnected to the frame 3310 without requiring a swivel elbow or a balland socket elbow typically used to address tube torque. This eliminatesan additional part which leads to overall weight reduction for thepatient interface 3000. Comfort is improved because the tube 4180 isbarely felt by the patient 1000 and it provides a greater freedom ofmovement for the patient 1000 before any tube drag acts to pull theseal-forming structure 3100 off the patient's face.

As described above, as the short tube 4180 is moved relative to thepatient interface 3000, it may create tube drag forces. The tube dragforces herein may comprise forces and/or moments, however it willunderstood that the term tube drag forces encompasses forces and/ormoments unless stated otherwise.

One of the causes of such tube drag forces may be bending of the shorttube 4180. For instance, bending created in the short tube 4180 as thepatient 1000 turns their body away from the PAP device 4000 may resultin tube drag forces at the patient interface 3000, potentiallydisrupting the seal, and/or creating discomfort to the patient.

To demonstrate the effect of tube drag forces, a simplifiedrepresentation of a system comprising a patient interface 3000 and ashort tube 4180 may be considered. It may be assumed that in thissystem, the patient interface is placed on the patient 1000, and theheadgear is de-coupled from the patient interface. In this case, anytube drag forces must be reacted by the patient interface 3000, whereinany moments for instance may be reacted as a force couple on the patient1000, and/or any forces may be reacted by equal and opposite reactionforces on the patient 1000.

The resulting tube drag forces at the patient interface 3000 may berelated to the structure of the short tube 4180. More specifically, asthe short tube 4180 is bent, the bending stiffness of the short tube4180 may affect the tube drag forces created at the patient interface3000.

Typically, when a cylindrical tubular object of constant cross sectionis fixed at a fixed end and loaded at a free end (i.e. cantilevered),the resulting force and moment at the fixed end can be described as

$d = \frac{{Pl}^{3}}{3\; {EI}}$

(disregarding gravity) wherein d is the deflection, P is the verticalforce, l is the length of the tube, E is the elastic modulus of thematerial and I is the second moment of area of the cross-section. Here,the resulting reactions at the fixed end would be a vertical force of Pin the opposite direction, and a moment of 1P.

Applying this to a system comprising a patient interface 3000 and ashort tube 4180, the reactions at the proximal end would be a verticalforce of P, and a moment of 1P, which may form a part of the tube dragforce. The above equation may be rearranged to

$P = {\frac{3d\; {EI}}{l^{3}}.}$

It then follows that for a given deflection d (i.e. for a given movementby the patient 1000), and tube length l, the tube drag force would beincreased as EI is increased, or as EI is decreased, tube drag would bedecreased.

For a circular tube of constant cross section, I may be calculated usingthe equation

$I = {\frac{\pi \left( {d_{o}^{4} - d_{i}^{4}} \right)}{64}.}$

Therefore, as an example, for a given inner diameter (d_(i)) of 15 mm, adecrease in the outer diameter (d_(o)) from 19 mm to 18 mm woulddecrease tube drag forces by approximately 32%. Similarly, a decrease inthe elastic modulus in the material used would achieve a decrease intube drag forces, although the relationship may be linear in this case.

Therefore, while the short tube 4180 in the present technology may notbe a circular tube of constant cross section, the total bendingstiffness of the short tube 4180 may be a result of geometric andmaterial properties of various portions of the short tube 4180, such asthe web of material 4172 and the helical coil 4174.

Reducing the bending stiffness of the short tube 4180 may result inweakening the structural integrity of the short tube 4180. That is, asan example, if the thickness of the web of material 4172 was changed byreducing the outer diameter of the short tube 4180, the bendingstiffness and therefore tube drag forces may be reduced, however thismay result in a more fragile construction of the short tube 4180 andlead to occlusion of the short tube 4180 during normal use.

Therefore an advantage of the present technology is the combination ofthe geometry and material of the short tube 4180 working to reducebending stiffness while maintaining appropriate strength to avoidocclusion and be durable.

The tube 4180 is substantially silent without a sticky noise/stictionthat may occur from axial compression and elongation of the tube 4180.One example to reduce or eliminate noise may be applying an additive toprevent the coils of the helical coil 4174 sticking to each other. Priortubes for patient interfaces have been known to suffer from this type ofnoise which can be annoying to the patient 1000 and their bed partner1100 when trying to sleep as it is intermittent noise. The tube 4180 isintended to be light weight to minimise tube drag forces caused by theweight of the tube 4180 under gravity. In one example of the presenttechnology, in the neutral state, the length of the tube 4180 may beabout 285 mm to 305 mm including the end cuffs 10610, 4190 and may weighabout 18.7 grams to 19.1 grams. Thus, the weight of the tube 4180 withthe end cuffs 10610, 4190 may be about 62.6 g/m to 65.6 g/m. There is noair leak between the tube 4180 and the end cuffs 10610, 4190 that areovermolded to the ends of the tube 4180. One of the end cuffs may be aswivel cuff 4190 to allow 360° relative rotation between the short tube4180 and the long tube 4178, while the other end cuff is a frame cuff10610 that does not swivel. The swivel cuff 4190 may have a bump offwhich provides an external tactile circumferential edge for an indexfinger of the patient 1000 to disengage the tube 4180 from a tubeadapter 4190 connected to a long tube 4178. The bump off may tolerate ahigher force to enhance durability of the swivel cuff 4190 and shorttube 4180 after repetitive engagement and disengagement from the longtube 4178.

Although a single helical coil 4174 has been described, it is envisagedthat more than helical coil may be provided for the tube 4180. Multiplehelical coils for the tube 4180 enable multi-start (double start, triplestart, etc), in other words, more than one thread. This may permit eachhelical coil to be made from a different material or have differentdimensions in order to enhance floppiness of the tube 4180 for reducingtube drag forces but also to prevent or resist kinking and occlusion byhaving a strong structure.

Alternative Patient Interfaces

Referring to FIGS. 30 to 36, a patient interface 3000 in an example ofthe present technology comprises a frame assembly 3001, a cushionassembly 3003 and a positioning and stabilising structure 3300. Thecushion assembly 3003 is removably engageable with the frame assembly3001. The positioning and stabilising structure 3300 is removablyengageable with the frame assembly 3001. The cushion assembly 3003 has aseal-forming structure 3100 and a plenum chamber 3200. The frame 3310has a connection port 3600 for connection to an air circuit 4170. Theframe 3310 provides a four (4) point connection to the positioning andstabilising structure 3300.

There are three retention features present on the external surface ofthe plenum chamber 3200, such that it retains in place a frame 3310 overthe external surface of the plenum chamber 3200. In FIG. 33, the frame3310 provides two pairs of opposing arms 10320, 10330 which are theupper arms 10320 and lower arms 10330. The upper arms 10320 provide anopposing pair of upper headgear connection points 10325 while the lowerarms 10330 provide an opposing pair of lower headgear connection points10331. The upper arms 10320 and their upper headgear connection points10325 are positioned such that they direct the force provided by theupper headgear straps 10230 into an upwards force vector that provides aforce to allow the patient interface 3000 to seal by the seal formingstructure 3100 on the upper lip and the cartilaginous framework (seeFIG. 33). The lower arms 10330 and their lower headgear connectionpoints 10331 are positioned such that they direct the lower headgearstraps 10220 into a downwardly directed force vector that provides acounteractive force to resist ride up of the patient interface 3000 andany seal disruptive forces in the upwards direction. This increasesstability of the mask 3000 and minimizes seal disruption. Thecounteractive force may also provide a downwards force vector, whichallows for increased stability in the tube up configurations of thepatient interface 3000 in use.

Y Shaped Headgear Connector 800

Referring to FIGS. 37 to 41, in another example of the presenttechnology, two headgear connectors 156 are operatively connected to theseal-forming structure 3100. The two headgear connectors 156 connect toa Y shaped headgear connector 800 which in turn is connected to headgearstraps 10220, 10230. The Y shaped headgear connector 800 directs a forcevector provided by headgear tension substantially in a directionparallel to the Frankfort horizontal direction. The force vectorsubstantially in the Frankfort horizontal direction provides an evendistribution of force in the vertical direction perpendicular to theFrankfort horizontal direction. The even distribution of force preventsany bias of force provided by headgear tension in an upwards ordownwards direction, thereby resisting ride up or ride down. Theincreased stability may allow the patient interface 3000 to be stablyused in the tube up configuration (short tube 4180 above the head) andtube down configuration.

The patient interface 3000 has a cushion assembly 3005 including a pairof Y shaped headgear connectors 800 that provide a four (4) pointconnection to a positioning and stabilising structure 3300. Thepositioning and stabilising structure 3300 connects to plenum chamber3200 via the two Y-shaped headgear connectors 800.

A connector may comprise a lug or interface adapted to receive a Yshaped headgear connector 800 on the positioning and stabilisingstructure 3300. It is understood that the Y shaped connector structure800 or the frame 3310 may be integrally formed with the cushion assembly3005 or form separate components for detachable engagement with thecushion assembly 3005.

The design of the Y shaped headgear connectors 800 and its relativepositioning of the headgear connection points 10331, 10325 located onthe arms 10320, 10330 of the frame 3310 directs the sealing force to thesealing region 251 in such a way so as to negate or eliminate the needfor a forehead support or vertical headgear strap. In other words, thesealing force is directed in a direction substantially parallel to theFrankfort horizontal.

The Y shaped headgear connectors 800 may be positioned on opposing sidesof the patient interface 3000 substantially in the Frankfort horizontaldirection such that the top of the Y extends towards but terminatesbefore the patient's ears. The Y shaped headgear connectors 800 may beformed of a flexible material such as silicone. Each Y shape headgearconnector 800 has two arms which provide an upper headgear strapconnection point 810 and lower headgear strap connection point 820 onopposing sides of the cushion assembly 3005. The upper headgear straps10230 and lower headgear straps 10220 run above and below the patient'sears respectively. The upper and lower headgear straps 10230, 10220subsequently connect to a neck strap 10227 to form a circular crownstrap 10225 to engage along the back or posterior of the patient's headalong, below or inferior to the occipital bone.

Pull-Through Prevention Feature 791

Turning to FIGS. 50 to 52, one form of pull-through prevention featurein accordance with an example of the present technology is an overlappedportion or pull-through prevention feature 791 positioned on the lowerheadgear straps 10220 in close proximity to the Velcro™-like connectionmechanism 950. The lower headgear straps 10220 connected to the lowerarms 10330 of the frame 3310 such that connection is maintained via thepull-through prevention feature 791. The pull-through prevention feature791 comprises a portion of the lower headgear straps 10220, in closeproximity to the Velcro™-like connection mechanism 950, wherein thelower headgear straps 10220 are overlapped onto themselves and connectedsuch that a loop is formed that provides the pull-through preventionfeature 791. The loop forming the pull-through prevention feature 791can be compressed to fit through the lower headgear strap connectionpoints 820 in one direction, such that it allows the lower headgearstraps 10220 to retain its connection to the frame 3310 by preventingthe lower headgear straps 10220 from pulling through the lower headgearstrap connection points 820 in an opposing direction to disconnect fromthe frame 3310.

The pull-through prevention feature can only be pulled through the lowerheadgear strap connection points 820 of the frame 3310 by compressingthe retaining loop of the pull-through prevention feature 791. The lowerheadgear straps 10220 may be connected to the lower arms 10330 of theframe 3310 by pulling through the hole provided by the lower headgearstrap connection points 820. Following connection, the loop of thepull-through prevention feature 791 expands to prevent the lowerheadgear straps 10220 from pulling through in the opposing direction todisconnect from the lower arms 10330 of the frame 3310.

The pull-through prevention feature 791 prevents the headgear strapsfrom pulling through the lower headgear strap connection points 820 andretains connection between the lower headgear straps 10220 and the lowerarms 10330 of the frame 3310.

The headgear comprises a pull-through prevention feature 791 on theheadgear straps 3301. After the pull-through preventions feature 791 areconnected to the headgear connectors by sliding through connection pointholes present on said headgear connectors, they cannot disconnect fromthe headgear connectors by sliding back out. The pull-through preventionfeature 791 act as retention features to retain the connection betweenthe headgear straps 3301 and the headgear connector. The pull-throughprevention feature 791 may comprise a thickened portion, overlappedportion or additional structure present on the ends of headgear straps3301 such that the thickened portion, overlapped portion or theadditional structure cannot fit through the connection point holes onthe headgear connector, thereby preventing the headgear straps 3301 fromcompletely pulling through and disconnecting from the headgearconnector.

Alternative Frame 3310

Referring to FIGS. 42 to 49, a frame 3310 may be formed of asubstantially rigid material. The frame 3310 may releasably engage withthe cushion assembly 3002 comprising a plenum chamber 3200. Engagementbetween the frame 3310 and the cushion assembly 3002 is by retentionfeatures 3244, 3245 of the cushion assembly 3002 engaging with frameconnection regions 3312, 3313 of the frame 3310. The frame connectionregions 3312, 3313 allows the retention feature 3244, 3245 to passthrough.

The frame 3310 comprises a substantially triangular perimeter portion720 with rounded corners and a connection port 3600 in the perimeterportion 720 for fitting over the cushion assembly 3002. The perimeterportion 720 has a curved profile to match that of the cushion assembly3002. The connection port 3600 is substantially circular to match thatof the anterior opening of the cushion assembly 3002. The frame 3310further comprises a pair of upper arms 10320 and a pair of lower arms10330. The upper arms 10320 extend from the top of the perimeter portion720 of the frame 3310 and terminate substantially in a middle positionbetween the patient's eyes and ears. The upper arms 10320 extend overthe cheeks of a patient in use and having a curved profile to fit theprofile of a patient's face so as to minimize obstruction. The upperarms 10320 extending outwardly from the patient's face so as to minimizecontact between the upper arms 10320, and the patient's face to avoiddiscomfort. In a further example, the upper arms 10320 extend between 80mm to 100 mm from the top of the perimeter portion 720 of the frame3310. The upper arms 10320 have upper headgear connections points 10325in the form of elongate slots to receive the upper headgear straps 10230to pass therethrough. The lower arms 10330 have lower headgearconnections points 10331 in the form of elongate slots to receive thelower headgear straps 10220 to pass therethrough. The headgearconnections points 10325, 10331 produce a four (4) point connection forthe positioning and stabilising structure 3300 to connect to the frame3310 and in turn connect to the cushion assembly 3002. The four-pointconnection improves stability of the patient interface 3000. The upperarms 10320 generally connect to the frame 3310 at a top frame connectionpoint 10305 of the frame 3310. A single upper headgear tension vector atthe top center position at the top frame connection point 10305, in adirection parallel to Frankfort horizontal direction prevents sealdisruption and is able to handle tube torque from the air circuit 4170.The two lower headgear connection points 10331 provide two parallellower headgear tension vectors.

The frame 3310 provides stability for the patient interface 3000 and ismade of a water clear transparent plastic material. The upper arms 10320sit below the patient's cheeks and the patient interface 3000 istherefore unobtrusive and opens up the patient's face.

Mask with Elbow Assembly 120

Referring to FIGS. 30 to 41, a patient interface 3000 in accordance withone example of the present technology comprises a positioning andstabilising structure 3300, an elbow assembly 120, an air circuit 4170and a cushion assembly 3003, 3005. The elbow assembly 120 has a vent forwashout of exhaled air including carbon dioxide. The positioning andstabilising structure 3300 may be adapted to support, stabilize and/orposition the cushion assembly 3003, 3005 on the patient's face.

The cushion assembly 3003, 3005 may be adapted to sealingly engage withthe patient's airways, including a patient's nose. The cushion assembly3003, 3005 may receive breathable gas from the air circuit 4170 and/orelbow assembly 120, and maintain position on the patient's face by thepositioning and stabilising structure 3300.

Upper Arm Sleeve 10312

Referring to FIG. 68, an upper arm sleeve 10312 is provided which ismade from a fabric textile material. The upper arm sleeves 10312 wrapsaround a portion of the upper arms 10320 that may be proximal to thepatient's cheeks in use. The upper arm sleeve 10312 is releasablyengageable with the upper arm 10320 and therefore may be washedseparately from the frame 3310. The upper arm sleeves 10312 cover theplastic material of the upper arms 10320 and prevent the inner sidesurface and top and bottom edges of the upper arms 10320 from directlytouching the patient's face in use. The fabric textile material of thearm sleeve 10312 feels soft and comfortable and is perceived by thepatient as less “medical” looking. This may lead to better therapycompliance. The upper arm sleeve 10312 may prevent or minimise facialmarking caused by the upper arms 10320 from a typical duration oftherapy, in particular, if the patient 1000 sleeps on one side ratherthan on their back. Also, the fabric textile material does not retainsurface heat and condensate from perspiration which may comparefavourably to direct contact between the patient's face and the plasticupper arm 10320. It is envisaged that the lower arms 10330 may also havea similar arm sleeve 10312.

Mask System

One or more of the mask components may configured and arranged togetherto decouple tube torque to minimise the likelihood of seal disruption.The short tube 4180 is able to decouple tube torque because of itsenhanced floppiness and ability to stretch. If tube torque is greaterthan what the short tube 4180 can decouple, the positioning andstabilising structure 3300 also decouples tube torque. The upper arms10320 of the frame 3310 may flex in the sagittal plane to decouple tubetorque. Also, the cushioning function of the plenum chamber 3200 and/orseal-forming structure 3100 will decouple some amount of tube torque.Any combination of two or more of these features improves the ability todecouple tube torque. The combination of all of these features furtherenhances the ability to decouple a larger amount of tube torque.

One or more of the mask components may be configured and arrangedtogether to improve comfort for the patient 1000. The short tube 4180 islight weight and the plenum chamber 3200 and seal-forming structure 3100are also light weight therefore the headgear tension provided by thepositioning and stabilising structure 3300 is not required to beuncomfortably high in order to provide a good seal. Reducing the needfor an elbow to connect the short tube 4180 to the frame 3310 alsoreduces overall weight of the patient interface 3000 which lowers thelevel of headgear tension required by the positioning and stabilisingstructure 3300. Also, the perception by the patient 1000 when a patientinterface 3000 is light weight is that it is “barely there” such that itdoes not feel like you are wearing a patient interface 3000 leading toless anxiety and claustrophobia. The shape and flexibility of the arms10320, 10330 provide comfort for the patient 1000 because they sit underthe cheek bones and also direct the headgear straps 3301 around thepatient's ears which may be sensitive facial regions for some patients1000. The headgear straps 3301 and upper arm sleeves 10312 are made froma fabric textile and feels good against the patient's skin because itdoes not retain surface heat and condensate from perspiration comparedto a plastic headgear strap. Also, because the headgear straps 3301 aremade from a fabric textile, it is less dense than a plastic materialwhich leads to weight and bulk reduction. Any combination of two or moreof these features improves comfort for the patient 1000. The combinationof all of these features greatly enhances comfort for the patient 1000.

One or more of the mask components may be configured and arrangedtogether to improve the chances of an optimal seal with the patient1000. This may lead to better therapy compliance and an increase inaverage daily usage by an additional 36 minutes. An optimal seal may beobtained through a combination of improved decoupling of tube torque andalso enhanced comfort for the patient 1000 as described above. Also, themaximum tilting range provided by the frame arms 10320, 10330 improvesthe chances of an optimal seal.

One or more of the mask components may be configured and arrangedtogether to improve the visual appeal of the patient interface 3000leading to better therapy compliance, especially for first time patients1000. The patient interface 3000 has a low profile and small footprinton the patient's face because the frame 3310 is not very wide and isalso curved to correspond to facial geometry and also there is anabsence of a forehead support. Any combination of two or more of thesefeatures improves the visual appeal of the patient interface 3000. Thecombination of all of these features greatly enhances the visual appealof the patient interface 3000.

One or more of the mask components may be configured and arrangedtogether to improve assembly and disassembly of the patient interface3000. The patient interface 3000 provides simplicity to the patient 1000as the patient interface provides a 3-piece mask system including twodetachable components from the frame 3310, which are the seal-formingstructure 3100 and headgear straps 3301. Less detachable components alsomeans that the patient interface 3000 is easy to assembly anddisassemble when the patient interface 3000 needs to be cleaned. Theframe 3310, plenum chamber 3200/seal-forming structure 3100 and headgearstraps 3301 may be washed individually and on different schedules, forexample, the plenum chamber 3200/seal-forming structure 3100 may bewashed more frequently than the headgear straps 3301. The shape andstructure of the components visually and tactilely suggest to thepatient 1000 how to assemble and disassemble the patient interface 3000in an intuitive manner. For example, the mating relationship between theplenum chamber 3200 and the frame 3310 which generates an audible clicksound when engagement is correct is intuitive to a patient 1000. Also,providing visual and tactile indicators on the frame 3310, plenumchamber 3200 and the positioning and stabilising structure 3300 andproviding magnetic headgear clips 10210 adds a further guide for thepatient 1000 to avoid incorrect assembly/disassembly ormisorientation/misalignment of mask components. Some of these featuresare especially advantageous for patients 1000 in a darkened environmentwho may have arthritic hands. For example, the audible click sound maybe heard, the touch and feel of the shapes of the mask components andtactile indicators or the sensation of magnetic attraction are alsouseful in low lighting conditions. Any combination of two or more ofthese features improves the simplicity of the patient interface 3000.The combination of all of these features greatly enhances the simplicityof the patient interface 3000.

In one example of the present technology, a frame assembly 3001 includesthe sub-assemblies of the frame 3310, short tube 4180, and vent 3400.The sub-assemblies of the frame assembly 3001 are permanently connectedto each other, for example, the vent 3400 integrated with the frame 3310and short tube 4180 are permanently connected to each other. A cushionassembly 3002 is removably engageable with the frame assembly 3001. Thecushion assembly 3002 includes the seal-forming structure 3100 andplenum chamber 3200. The headgear straps 3301 are removably engageablewith the frame assembly 3001, in particular, with the arms 10320, 10330of the frame 3310.

FIGS. 131 to 137 show various views of a patient interface in accordancewith one form of the present technology including one or more aspects asdescribed above.

Pap Device 4000

A PAP device 4000 in accordance with one aspect of the presenttechnology comprises mechanical and pneumatic components 4100,electrical components 4200 and is programmed to execute one or morealgorithms 4300. The PAP device may have an external housing 4010,formed in two parts, an upper portion 4012 of the external housing 4010,and a lower portion 4014 of the external housing 4010. In alternativeforms, the external housing 4010 may include one or more panel(s) 4015.The PAP device 4000 may comprise a chassis 4016 that supports one ormore internal components of the PAP device 4000. In one form a pneumaticblock 4020 is supported by, or formed as part of the chassis 4016. ThePAP device 4000 may include a handle 4018.

The pneumatic path of the PAP device 4000 may comprise an inlet airfilter 4112, an inlet muffler, a controllable pressure device capable ofsupplying air at positive pressure (e.g., a controllable blower 4142),and an outlet muffler. One or more pressure sensors and flow sensors maybe included in the pneumatic path.

The pneumatic block 4020 may comprise a portion of the pneumatic paththat is located within the external housing 4010.

The PAP device 4000 may have an electrical power supply 4210 and one ormore input devices 4220. Electrical components 4200 may be mounted on asingle Printed Circuit Board Assembly (PCBA) 4202. In an alternativeform, the PAP device 4000 may include more than one PCBA 4202.

Pap Device Mechanical & Pneumatic Components 4100 Air Filter(s) 4110

A PAP device 4000 in accordance with one form of the present technologymay include an air filter 4110, or a plurality of air filters 4110.

In one form, an inlet air filter 4112 is located at the beginning of thepneumatic path upstream of a controllable blower 4142. See FIG. 3 c.

In one form, an outlet air filter 4114, for example an antibacterialfilter, is located between an outlet of the pneumatic block 4020 and apatient interface 3000. See FIG. 3 c.

Pressure Device 4140

In a form of the present technology, a pressure device for producing aflow of air at positive pressure is a controllable blower 4142. Forexample the blower 4142 may include a brushless DC motor with one ormore impellers housed in a volute. The blower 4142 may be capable ofdelivering a supply of air, for example about 120 litres/minute, at apositive pressure in a range from about 4 cm H2O to about 20 cm H2O, orin other forms up to about 30 cm H2O.

Humidifier 5000 Humidifier Overview

In one form of the present technology there is provided a humidifier5000, as shown in FIG. 3 b, that may comprise a water reservoir and aheating plate.

Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

General

Air: In certain forms of the present technology, air supplied to apatient may be atmospheric air, and in other forms of the presenttechnology atmospheric air may be supplemented with oxygen.

Continuous Positive Airway Pressure (CPAP): CPAP treatment will be takento mean the application of a supply of air or breathable gas to theentrance to the airways at a pressure that is continuously positive withrespect to atmosphere, and preferably approximately constant through arespiratory cycle of a patient. In some forms, the pressure at theentrance to the airways will vary by a few centimeters of water within asingle respiratory cycle, for example being higher during inhalation andlower during exhalation. In some forms, the pressure at the entrance tothe airways will be slightly higher during exhalation, and slightlylower during inhalation. In some forms, the pressure will vary betweendifferent respiratory cycles of the patient, for example being increasedin response to detection of indications of partial upper airwayobstruction, and decreased in the absence of indications of partialupper airway obstruction.

Aspects of PAP Devices

Air circuit: A conduit or tube constructed and arranged in use todeliver a supply of air or breathable gas between a PAP device and apatient interface. In particular, the air circuit may be in fluidconnection with the outlet of the pneumatic block and the patientinterface. The air circuit may be referred to as air delivery tube. Insome cases there may be separate limbs of the circuit for inhalation andexhalation. In other cases a single limb is used.

APAP: Automatic Positive Airway Pressure. Positive airway pressure thatis continually adjustable between minimum and maximum limits, dependingon the presence or absence of indications of SDB events.

Blower or flow generator: A device that delivers a flow of air at apressure above ambient pressure.

Controller: A device, or portion of a device that adjusts an outputbased on an input. For example one form of controller has a variablethat is under control—the control variable—that constitutes the input tothe device. The output of the device is a function of the current valueof the control variable, and a set point for the variable. Aservo-ventilator may include a controller that has ventilation as aninput, a target ventilation as the set point, and level of pressuresupport as an output. Other forms of input may be one or more of oxygensaturation (SaO2), partial pressure of carbon dioxide (PCO2), movement,a signal from a photoplethysmogram, and peak flow. The set point of thecontroller may be one or more of fixed, variable or learned. Forexample, the set point in a ventilator may be a long term average of themeasured ventilation of a patient. Another ventilator may have aventilation set point that changes with time. A pressure controller maybe configured to control a blower or pump to deliver air at a particularpressure.

Therapy: Therapy in the present context may be one or more of positivepressure therapy, oxygen therapy, carbon dioxide therapy, control ofdead space, and the administration of a drug.

Motor: A device for converting electrical energy into rotary movement ofa member. In the present context the rotating member is an impeller,which rotates in place around a fixed axis so as to impart a pressureincrease to air moving along the axis of rotation.

Positive Airway Pressure (PAP) device: A device for providing a supplyof air at positive pressure to the airways.

Transducers: A device for converting one form of energy or signal intoanother. A transducer may be a sensor or detector for convertingmechanical energy (such as movement) into an electrical signal. Examplesof transducers include pressure sensors, flow sensors, carbon dioxide(CO2) sensors, oxygen (O2) sensors, effort sensors, movement sensors,noise sensors, a plethysmograph, and cameras.

Aspects of the Respiratory Cycle

Apnea: Preferably, apnea will be said to have occurred when flow fallsbelow a predetermined threshold for a duration, e.g. 10 seconds. Anobstructive apnea will be said to have occurred when, despite patienteffort, some obstruction of the airway does not allow air to flow. Acentral apnea will be said to have occurred when an apnea is detectedthat is due to a reduction in breathing effort, or the absence ofbreathing effort.

Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

Effort (breathing): Preferably breathing effort will be said to be thework done by a spontaneously breathing person attempting to breathe.

Expiratory portion of a breathing cycle: The period from the start ofexpiratory flow to the start of inspiratory flow.

Flow limitation: Preferably, flow limitation will be taken to be thestate of affairs in a patient's respiration where an increase in effortby the patient does not give rise to a corresponding increase in flow.Where flow limitation occurs during an inspiratory portion of thebreathing cycle it may be described as inspiratory flow limitation.Where flow limitation occurs during an expiratory portion of thebreathing cycle it may be described as expiratory flow limitation.

Hypopnea: Preferably, a hypopnea will be taken to be a reduction inflow, but not a cessation of flow. In one form, a hypopnea may be saidto have occurred when there is a reduction in flow below a threshold fora duration. In one form in adults, the following either of the followingmay be regarded as being hypopneas:

(i) a 30% reduction in patient breathing for at least 10 seconds plus anassociated 4% desaturation; or(ii) a reduction in patient breathing (but less than 50%) for at least10 seconds, with an associated desaturation of at least 3% or anarousal.

Inspiratory portion of a breathing cycle: Preferably the period from thestart of inspiratory flow to the start of expiratory flow will be takento be the inspiratory portion of a breathing cycle.

Patency (airway): The degree of the airway being open, or the extent towhich the airway is open. A patent airway is open. Airway patency may bequantified, for example with a value of one (1) being patent, and avalue of zero (0), being closed.

Positive End-Expiratory Pressure (PEEP): The pressure above atmospherein the lungs that exists at the end of expiration.

Peak flow (Qpeak): The maximum value of flow during the inspiratoryportion of the respiratory flow waveform.

Respiratory flow, airflow, patient airflow, respiratory airflow (Qr):These synonymous terms may be understood to refer to the PAP device'sestimate of respiratory airflow, as opposed to “true respiratory flow”or “true respiratory airflow”, which is the actual respiratory flowexperienced by the patient, usually expressed in litres per minute.

Tidal volume (Vt): The volume of air inhaled or exhaled during normalbreathing, when extra effort is not applied.

(inhalation) Time (Ti): The duration of the inspiratory portion of therespiratory flow waveform.

(exhalation) Time (Te): The duration of the expiratory portion of therespiratory flow waveform.

(total) Time (Ttot): The total duration between the start of theinspiratory portion of one respiratory flow waveform and the start ofthe inspiratory portion of the following respiratory flow waveform.

Typical recent ventilation: The value of ventilation around which recentvalues over some predetermined timescale tend to cluster, that is, ameasure of the central tendency of the recent values of ventilation.

Upper airway obstruction (UAO): includes both partial and total upperairway obstruction. This may be associated with a state of flowlimitation, in which the level of flow increases only slightly or mayeven decrease as the pressure difference across the upper airwayincreases (Starling resistor behaviour).

Ventilation (Vent): A measure of the total amount of gas being exchangedby the patient's respiratory system, including both inspiratory andexpiratory flow, per unit time. When expressed as a volume per minute,this quantity is often referred to as “minute ventilation”. Minuteventilation is sometimes given simply as a volume, understood to be thevolume per minute.

PAP Device Parameters

Flow rate: The instantaneous volume (or mass) of air delivered per unittime. While flow rate and ventilation have the same dimensions of volumeor mass per unit time, flow rate is measured over a much shorter periodof time. Flow may be nominally positive for the inspiratory portion of abreathing cycle of a patient, and hence negative for the expiratoryportion of the breathing cycle of a patient. In some cases, a referenceto flow rate will be a reference to a scalar quantity, namely a quantityhaving magnitude only. In other cases, a reference to flow rate will bea reference to a vector quantity, namely a quantity having bothmagnitude and direction. Flow will be given the symbol Q. Total flow,Qt, is the flow of air leaving the PAP device. Vent flow, Qv, is theflow of air leaving a vent to allow washout of exhaled gases. Leak flow,Ql, is the flow rate of unintentional leak from a patient interfacesystem. Respiratory flow, Qr, is the flow of air that is received intothe patient's respiratory system.

Leak: Preferably, the word leak will be taken to be a flow of air to theambient. Leak may be intentional, for example to allow for the washoutof exhaled CO₂. Leak may be unintentional, for example, as the result ofan incomplete seal between a mask and a patient's face.

Pressure: Force per unit area. Pressure may be measured in a range ofunits, including cm H₂O, g-f/cm², hectopascal. 1 cm H₂O is equal to 1g-f/cm² and is approximately 0.98 hectopascal. In this specification,unless otherwise stated, pressure is given in units of cm H₂O. For nasalCPAP treatment of OSA, a reference to treatment pressure is a referenceto a pressure in the range of about 4-20 cm H₂O, or about 4-30 cm H₂O.The pressure in the patient interface is given the symbol Pm.

Sound Power: The energy per unit time carried by a sound wave. The soundpower is proportional to the square of sound pressure multiplied by thearea of the wavefront. Sound power is usually given in decibels SWL,that is, decibels relative to a reference power, normally taken as 10⁻¹²watt.

Sound Pressure: The local deviation from ambient pressure at a giventime instant as a result of a sound wave travelling through a medium.Sound power is usually given in decibels SPL, that is, decibels relativeto a reference power, normally taken as 20×10⁻⁶ pascal (Pa), consideredthe threshold of human hearing.

Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricula or Pinna: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankfurthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the greater alarcartilage.

Greater alar cartilage: A plate of cartilage lying below the lateralnasal cartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear) dividing the body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramentale: The point of greatest concavity in the midline of thelower lip between labrale inferius and soft tissue pogonion

Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama occipitalis.

Orbit: The bony cavity in the skull to contain the eyeball.

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx) (the nasal part of the pharynx), the oropharynx(mesopharynx) (the oral part of the pharynx), and the laryngopharynx(hypopharynx).

Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression molded silicone rubber (CMSR). One form ofcommercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, a preferred form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240

Polycarbonate: a typically transparent thermoplastic polymer ofBisphenol-A Carbonate.

Aspects of a Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: A conduit that directs an axis of flow of air to change directionthrough an angle. In one form, the angle may be approximately 90degrees. In another form, the angle may be less than 90 degrees. Theconduit may have an approximately circular cross-section. In anotherform the conduit may have an oval or rectangular cross-section.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a positioningand stabilising structure. A mask frame may be a non-airtight loadbearing structure in the mask. However, some forms of mask frame mayalso be air-tight.

Positioning and stabilising structure: Positioning and stabilisingstructure will be taken to mean a form of positioning and stabilizingstructure designed for use on a head. Preferably the positioning andstabilising structure comprises a collection of one or more struts, tiesand stiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to a mean portion ofa patient interface having walls enclosing a volume of space, the volumehaving air therein pressurised above atmospheric pressure in use. Ashell may form part of the walls of a mask plenum chamber. In one form,a region of the patient's face forms one of the walls of the plenumchamber.

Seal: The noun form (“a seal”) will be taken to mean a structure orbarrier that intentionally resists the flow of air through the interfaceof two surfaces. The verb form (“to seal”) will be taken to mean toresist a flow of air.

Shell: A shell will preferably be taken to mean a curved structurehaving bending, tensile and compressive stiffness, for example, aportion of a mask that forms a curved structural wall of the mask.Preferably, compared to its overall dimensions it is relatively thin. Insome forms, a shell may be faceted. Preferably such walls are airtight,although in some forms they may not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel: (noun) A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. Preferably there islittle or no leak flow of air from the swivel in use.

Tie: A tie will be taken to be a structural component designed to resisttension.

Vent: (noun) the structure that allows a deliberate controlled rate leakof air from an interior of the mask, or conduit to ambient air, to allowwashout of exhaled carbon dioxide (CO₂) and supply of oxygen (O₂).

Terms Used in Relation to Patient Interface

Curvature (of a surface): A region of a surface having a saddle shape,which curves up in one direction and curves down in a differentdirection, will be said to have a negative curvature. A region of asurface having a dome shape, which curves the same way in two principledirections, will be said to have a positive curvature. A flat surfacewill be taken to have zero curvature.

Floppy: A quality of a material, structure or composite that is thecombination of features of:

Readily conforming to finger pressure.

Unable to retain its shape when caused to support its own weight.

Not rigid.

Able to be stretched or bent elastically with little effort.

The quality of being floppy may have an associated direction, hence aparticular material, structure or composite may be floppy in a firstdirection, but stiff or rigid in a second direction, for example asecond direction that is orthogonal to the first direction.

Resilient: Able to deform substantially elastically, and to releasesubstantially all of the energy upon unloading, within a relativelyshort period of time such as 1 second.

Rigid: Not readily deforming to finger pressure, and/or the tensions orloads typically encountered when setting up and maintaining a patientinterface in sealing relationship with an entrance to a patient'sairways.

Semi-rigid: means being sufficiently rigid to not substantially distortunder the effects of mechanical forces typically applied during positiveairway pressure therapy.

Other Remarks

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it. It shouldbe further understood that any and all stated values may be variable byup 10-20% from the value stated.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being preferably used toconstruct a component, obvious alternative materials with similarproperties may be used as a substitute. Furthermore, unless specified tothe contrary, any and all components herein described are understood tobe capable of being manufactured and, as such, may be manufacturedtogether or separately.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated by reference todisclose and describe the methods and/or materials which are the subjectof those publications. The publications discussed herein are providedsolely for their disclosure prior to the filing date of the presentapplication. Nothing herein is to be construed as an admission that thepresent technology is not entitled to antedate such publication byvirtue of prior invention. Further, the dates of publication providedmay be different from the actual publication dates, which may need to beindependently confirmed.

Moreover, in interpreting the disclosure, all terms should beinterpreted in the broadest reasonable manner consistent with thecontext. In particular, the terms “comprises” and “comprising” should beinterpreted as referring to elements, components, or steps in anon-exclusive manner, indicating that the referenced elements,components, or steps may be present, or utilized, or combined with otherelements, components, or steps that are not expressly referenced.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

REFERENCE SIGNS LIST

-   -   elbow assembly 120    -   headgear connectors 156    -   attachment region 158    -   sealing region 251    -   nose ridge region 252    -   sides of the nose region 253    -   corners of the nose region 254    -   top lip region 255    -   inner (superior) edge 260(i)    -   outer (inferior) edge 260(o)    -   membrane 260-1    -   membrane 260-2    -   membrane 260-3    -   undercushion structure 265    -   sealing flap 270    -   orifice 275    -   upper orifice portion 275(1)    -   lower orifice portion 275(2)    -   outer edge 280(i)    -   inner edge 280(o)    -   side wall region 457    -   triangular perimeter portion 720    -   Y shaped headgear connector 800    -   upper headgear strap connection point 810    -   lower headgear strap connection point 820    -   hook and loop connection mechanism 950    -   patient 1000    -   bed partner 1100    -   patient interface 3000    -   frame assembly 3001    -   cushion assembly 3002    -   cushion assembly 3003    -   cushion assembly 3005    -   seal-forming structure 3100    -   nasal cradle 3101    -   superior sealing portion 3102    -   inferior sealing portion 3104    -   sealing flange 3110    -   support flange 3120    -   plenum chamber 3200    -   connection portion 3202    -   perimeter 3210    -   tongue portion 3211    -   channel portion 3211.1    -   frame connection region 3213    -   marginal edge 3220    -   plenum connection region 3240    -   retaining structure 3242    -   wide retention feature 3244    -   narrow retention feature 3245    -   barb 3246    -   leading surface 3246.1    -   trailing surface 3246.2    -   nominal vertical axis 3246.4    -   sealing lip 3250    -   ribs 3294    -   notches 3295    -   positioning and stabilising structure 3300    -   headgear straps 3301    -   frame 3310    -   wide frame connection region 3312    -   lead-in surface 3312.1    -   retaining surface 3312.2    -   narrow frame connection region 3313    -   interfering portion 3314    -   vent 3400    -   vent holes 3405    -   connection port 3600    -   PAP device 4000    -   external housing 4010    -   upper portion of the external housing 4012    -   lower portion of the external housing 4014    -   panel 4015    -   chassis 4016    -   handle 4018    -   pneumatic block 4020    -   pneumatic components 4100    -   air filter 4110    -   inlet air filter 4112    -   outlet air filter 4114    -   pressure device 4140    -   controllable blower 4142    -   air circuit 4170    -   web of material 4172    -   helical coil 4174    -   inner portion of the bend 4176    -   long tube 4178    -   outer portion of the bend 4179    -   short tube 4180    -   humped portion 4181    -   peak of the fold 4182    -   slanted portion 4183    -   outer surface of the helical coil 4184    -   supplemental oxygen port 4185    -   fold line 4186    -   swivel cuff 4190    -   electrical components 4200    -   printed circuit assembly (PCBA) 4202    -   electrical power supply 4210    -   input device 4220    -   algorithms 4300    -   humidifier 5000    -   headgear clip 10210    -   mechanical retention member 10215    -   magnet 10216    -   void 10217    -   cross-bar 10218    -   lower headgear strap 10220    -   lower connection portions 10221    -   upper connection portions 10222    -   thinned connecting portions 10223    -   top crown strap 10225    -   lateral crown straps 10226    -   neck strap 10227    -   major side edges 10228    -   major side edges 10229    -   upper headgear strap 10230    -   minor side edges 10231    -   minor side edges 10232    -   top frame connection point 10305    -   elongate void 10306    -   first curved section 10307    -   first bend 10308    -   straight section 10309    -   second bend 10310    -   second curved section 10311    -   upper arm sleeve 10312    -   narrower central region 10313    -   ring member 10315    -   joining member 10316    -   lower arm connection points 10317    -   upper arm 10320    -   distal end 10323    -   upper headgear connection point 10325    -   lower arm 10330    -   lower headgear connection point 10331    -   cylindrical portion 10334    -   raised surface 10335    -   magnet 10340    -   outer radial wall 10350    -   inner radial wall 10351    -   radial channel 10352    -   stop surface 10353    -   tracks 10355    -   annular rib 10360    -   short tube cuff 10610    -   groove 16011    -   Patent Literature

1. A frame assembly for a patient interface for delivery of a supply ofpressurised air or breathable gas to an entrance of a patient's nasalairways only, the frame assembly comprising: a ring member; lower armsextending from lower arm connection points radially positioned on thering member; a joining member extending posteriorly from the ring memberat an upper position on the ring member; and upper arms extending froman upper arm connection point at a distal end of the joining member suchthat the lower arm connection points are in a position anterior from theupper arm connection point, the upper arms adapted to extend over thecheeks of the patient in use; wherein the upper arm connection point andlower arm connection points are spaced apart at a predetermined distanceto provide a maximum tilting range for the frame assembly relative tothe patient's face, and wherein a center of rotation or pivot point ofthe frame assembly is provided at a lower side of the frame assembly. 2.The frame assembly of claim 1, wherein the upper arms are releasablyengageably with upper headgear straps and the upper arms direct atension vector of the upper headgear straps in a direction substantiallyparallel to the Frankfort horizontal direction and avoid extendingacross the patient's ears.
 3. The frame assembly of claim 1, wherein theupper arm connection point is at an upper most position on the ringmember, and the lower arm connection points are positioned about 80° toabout 160° from the upper arm connection point.
 4. The frame assembly ofclaim 3, wherein the lower arm connection points are positioned about90° from the upper arm connection point.
 5. The frame assembly of claim1, wherein the upper arms are spaced apart from each other toaccommodate a plurality of sizes for a cushion assembly that isreleasably attachable to the frame assembly.
 6. The frame assembly ofclaim 1, wherein the upper arms is more flexible in the sagittal planethan other planes to accommodate various patient face widths.
 7. Theframe assembly of claim 1, wherein the upper arms are more flexible thanthe lower arms.
 8. The frame assembly of claim 1, wherein the lower armshave a distal free end, each distal free end having a magnet.
 9. Theframe assembly of claim 8, wherein the magnet is fully encased withinthe lower arm.
 10. The frame assembly of claim 9, wherein the encasementof the magnet provides a raised surface extending anteriorly, and theraised surface enables a mechanical engagement to a circumferential edgeof a headgear clip.
 11. The frame assembly of claim 10, wherein themagnet and the raised surface have a substantially circular or ovalcross-section which enables the headgear clip to rotate relative tolower arm when magnetically engaged to minimise a lower headgear strapfrom twisting when headgear tension is applied.
 12. The frame assemblyof claim 1, wherein the upper arms have a distal free end, each distalfree end having a magnet.
 13. The frame assembly of claim 1, wherein thering member has a multi-hole vent radially disposed around a connectionport for connection to an air circuit.
 14. The frame assembly of claim13, wherein the air circuit comprises a gas delivery tube with a cuffthat is connected to the ring member, the ring member having a radialwall projecting posteriorly that segregates the flowpath of pressurisedair from the flowpath of exhaust via the vent to reduce cyclic noise.15. The frame assembly of claim 14, wherein the cuff is non-rotatablyconnected to the ring member.
 16. The frame assembly of claim 14,wherein the cuff is permanently connected to the ring member viamechanical interlock.
 17. The frame assembly of claim 1, wherein theframe assembly is releasably engageable with a cushion assembly, thecushion assembly comprising: a retaining structure for repeatableengagement with and disengagement from a frame member; and aseal-forming structure permanently connected to the retaining structure,the seal-forming structure serving both nares of the patient with asingle orifice; wherein the seal-forming structure is made from a firstmaterial and the retaining structure is made from a second material thatis different from the first material and is more rigid than the firstmaterial; and wherein an increase in air pressure within the cushionassembly causes a sealing force between the seal-forming structure andthe frame member to increase.
 18. The frame assembly of claim 17,wherein the seal-forming structure has a substantially flat lower wallto alleviate pressure on the patient's upper lip.
 19. The frame assemblyof claim 17, wherein the frame member and the retaining structure arecomprised of a semi-rigid material to provide a releasable hard-to-hardconnection.
 20. The frame assembly of any claim 17, wherein the cushionassembly comprises a sealing lip that seals against the frame memberwhen the retaining structure and frame member are attached to oneanother, and when air pressure increases within the cushion assembly,the sealing force is increased.
 21. The frame assembly of claim 1,further comprising a tube for the delivery of the supply of pressurisedair or breathable gas, the tube being connected to the frame assemblywithout a swivel elbow.
 22. The frame assembly of claim 21, wherein thetube is permanently connected to the frame assembly.
 23. A patientinterface for sealed delivery of a flow of breathable gas at acontinuously positive pressure with respect to ambient air pressure toan entrance to the patient's airways including at least entrance of apatient's nares, wherein the patient interface is configured to maintaina therapy pressure in a range of about 4 cm H₂O to about 30 cm H₂O aboveambient air pressure in use, throughout the patient's respiratory cycle,while the patient is sleeping, to ameliorate sleep disordered breathing;said patient interface comprising: a cushion assembly including aseal-forming structure adapted to form a seal against the patient'sairways and a plenum chamber pressurised at a pressure above ambientpressure in use; a positioning and stabilising structure to maintain thecushion assembly in sealing contact with an area surrounding an entranceto the patient's airways while maintaining a therapeutic pressure at theentrance to the patient's airways; a gas washout vent configured toallow a flow of patient exhaled CO₂ to an exterior of the patientinterface to minimise rebreathing of exhaled CO₂ by the patient; and theframe assembly according to claim
 1. 24. Apparatus for treating arespiratory disorder comprising: a patient interface as claimed in claim23; an air circuit; and a source of air at positive pressure. 25-103.(canceled)